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Franco CHIARALUCE

Pubblicazioni

Franco CHIARALUCE

 

312 pubblicazioni classificate nel seguente modo:

Nr. doc. Classificazioni
195 4 Contributo in Atti di Convegno (Proceeding)
84 1 Contributo su Rivista
16 5 Altro
14 2 Contributo in Volume
2 3 Libro
1 6 Brevetti
Anno Risorsa
Coded transmissions for space links affected by solar scintillation: Baseband analysis
INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING
Autore/i: Baldi, Marco; Chiaraluce, Franco; Maturo, Nicola; Ricciutelli, Giacomo; Ardito, Alessandro; Barbaglio, Francesco; Finocchiaro, Stefano; Simone, Lorenzo; Abelló, Ricard; De Vicente, Javier; Mercolino, Mattia
Classificazione: 1 Contributo su Rivista
Abstract: Summary A thorough analysis of the behavior of error-correcting codes over space links affected by solar scintillation is presented. The relevant channel parameters are fixed through the development of a model based on real missions' data. Both telecommand and telemetry links are considered in fast and slow fading conditions. Besides classical coherent modulation schemes, the possibility to use noncoherent modulation schemes is considered, to eliminate the problem of phase tracking. For the case of channels with very slow fading, the use of external interleavers or erasure coding is proposed to cope with error bursts.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/263392 Collegamento a IRIS

2019 Code-based physical layer secret key generation in passive optical networks
AD HOC NETWORKS
Autore/i: Baldi, Marco; Chiaraluce, Franco; Incipini, Lorenzo; Ruffini, Marco
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/263398 Collegamento a IRIS

2019 Hard-decision iterative decoding of LDPC codes with bounded error rate
Proc. IEEE ICC 2019
Autore/i: Santini, Paolo; Battaglioni, Massimo; Baldi, Marco; Chiaraluce, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Differently from bounded-distance decoders used for algebraic codes, iterative decoders used for low-density parity-check (LDPC) codes are not characterized by a deterministic decoding radius. Therefore, the error rates of LDPC-coded transmissions are usually estimated heuristically through simulations.This is adequate for many applications like wireless communications, where a frame error rate (FER) in the order of 10^(-6) or higher is usually targeted. However, lower values of FER can barely be assessed through simulations, and this limits the use of LDPC codes in applications requiring a lower FER, like optical communications and code-based cryptography. In this paper we introduce and study a version of the classic bit flipping (BF) decoder for which we are able to devise and develop a theoretical characterization of the FER. In addition, we consider a two-iteration hard-decision decoder for LDPC codes derived from BF, and discuss its error rate performance. Our results are validated through numerical simulations.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266392 Collegamento a IRIS

2019 Security of generalised Reed–Solomon code-based cryptosystems
IET INFORMATION SECURITY
Autore/i: Baldi, Marco; Chiaraluce, Franco; Rosenthal, Joachim; Santini, Paolo; Schipani, Davide
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/263712 Collegamento a IRIS

2018 Interleaver design for short concatenated codes
IEEE COMMUNICATIONS LETTERS
Autore/i: Ricciutelli, Giacomo; Baldi, Marco; Chiaraluce, Franco
Classificazione: 1 Contributo su Rivista
Abstract: The choice of the interleaver may significantly affect the performance of short codes when they are used in serial concatenation. By focusing on the minimum distance of the overall concatenated code, we propose an algorithmic method for the design of good interleavers. As a valuable example of application, we consider the case of polar codes concatenated with cyclic redundancy check codes. For these codes, the method we propose is compared with classical approaches based on random searches to assess its advantages, which are also confirmed through examples of practical coded transmissions over the binary erasure channel.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259762 Collegamento a IRIS

2018 Assessing and Countering Reaction Attacks Against Post-Quantum Public-Key Cryptosystems Based on QC-LDPC Codes
Cryptology and Network Security
Autore/i: Santini, Paolo; Baldi, Marco; Chiaraluce, Franco
Editore: Springer
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/260223 Collegamento a IRIS

2018 LEDAkem: A Post-quantum Key Encapsulation Mechanism Based on QC-LDPC Codes
Post-Quantum Cryptography. PQCrypto 2018.
Autore/i: Baldi, Marco; Barenghi, Alessandro; Chiaraluce, Franco; Pelosi, Gerardo; Santini, Paolo
Editore: Springer
Luogo di pubblicazione: Cham
Classificazione: 2 Contributo in Volume
Abstract: This work presents a new code-based key encapsulation mechanism (KEM) called LEDAkem. It is built on the Niederreiter cryptosystem and relies on quasi-cyclic low-density parity-check codes as secret codes, providing high decoding speeds and compact keypairs. LEDAkem uses ephemeral keys to foil known statistical attacks, and takes advantage of a new decoding algorithm that provides faster decoding than the classical bit-flipping decoder commonly adopted in this kind of systems. The main attacks against LEDAkem are investigated, taking into account quantum speedups. Some instances of LEDAkem are designed to achieve different security levels against classical and quantum computers. Some performance figures obtained through an efficient C99 implementation of LEDAkem are provided.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/257853 Collegamento a IRIS

2018 Design and Analysis of Time-Invariant SC-LDPC Convolutional Codes with Small Constraint Length
IEEE TRANSACTIONS ON COMMUNICATIONS
Autore/i: Battaglioni, Massimo; Tasdighi, Alireza; Cancellieri, Giovanni; Chiaraluce, Franco; Baldi, Marco
Classificazione: 1 Contributo su Rivista
Abstract: In this paper, we deal with time-invariant spatially coupled low-density parity-check convolutional codes (SC-LDPCCCs). Classic design approaches usually start from quasi-cyclic low-density parity-check (QC-LDPC) block codes and exploit suitable unwrapping procedures to obtain SC-LDPC-CCs. We show that the direct design of the SC-LDPC-CCs syndrome former matrix or, equivalently, the symbolic parity-check matrix, leads to codes with smaller syndrome former constraint lengths with respect to the best solutions available in the literature. We provide theoretical lower bounds on the syndrome former constraint length for the most relevant families of SC-LDPCCCs, under constraints on the minimum length of cycles in their Tanner graphs. We also propose new code design techniques that approach or achieve such theoretical limits.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251878 Collegamento a IRIS

2018 Efficient search of compact QC-LDPC and SC-LDPC convolutional codes with large girth
IEEE COMMUNICATIONS LETTERS
Autore/i: Tadayon, Mohammad H.; Tasdighi, Alireza; Battaglioni, Massimo; Baldi, Marco; Chiaraluce, Franco
Classificazione: 1 Contributo su Rivista
Abstract: We propose a low-complexity method to find quasi-cyclic low-density parity-check block codes with girth 10 or 12 and length shorter than those designed through classical approaches. The method is extended to time-invariant spatially coupled low-density parity-check convolutional codes, permitting to achieve small syndrome former constraint lengths. Several numerical examples are given to show its effectiveness.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/257854 Collegamento a IRIS

2018 Hindering reaction attacks by using monomial codes in the McEliece cryptosystem
Proc. IEEE ISIT 2018
Autore/i: Santini, Paolo; Baldi, Marco; Cancellieri, Giovanni; Chiaraluce, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper we study recent reaction attacks against QC-LDPC and QC-MDPC code-based cryptosystems, which allow an opponent to recover the private parity-check matrix through its distance spectrum by observing a sufficiently high number of decryption failures. We consider a special class of codes, known as monomial codes, to form private keys with the desirable property of having a unique and complete distance spectrum. We verify that for these codes the problem of recovering the secret key from the distance spectrum is equivalent to that of finding cliques in a graph, and use this equivalence to prove that current reaction attacks are not applicable when codes of this type are used in the McEliece cryptosystem.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/258706 Collegamento a IRIS

2018 Compact QC-LDPC Block and SC-LDPC Convolutional Codes for Low-Latency Communications
Proc. IEEE 29th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC 2018)
Autore/i: Battaglioni, Massimo; Tasdighi, Alireza; Baldi, Marco; Tadayon, Mohammad H.; Chiaraluce, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Low decoding latency and complexity are two important requirements of channel codes used in many applications, like machine-to-machine communications. In this paper, we show how these requirements can be fulfilled by using some special quasi-cyclic low-density parity-check block codes and spatially coupled low-density parity-check convolutional codes that we denote as compact. They are defined by parity-check matrices designed according to a recent approach based on sequentially multiplied columns. This method allows obtaining codes with girth up to 12. Many numerical examples of practical codes are provided.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259763 Collegamento a IRIS

2017 A probabilistic small model theorem to assess confidentiality of dispersed cloud storage
Proc. ICTCS 2017 and CILC 2017
Autore/i: Baldi, Marco; Bartocci, Ezio; Chiaraluce, Franco; Cucchiarelli, Alessandro; Senigagliesi, Linda; Spalazzi, Luca; Spegni, Francesco
Editore: CEUR-WS
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Recent developments in cloud architectures and security concerns have originated new models of online storage clouds based on data dispersal algorithms. According to these lgorithms the data is divided into several slices that are distributed among remote and independent storage nodes. Ensuring confidentiality in this context is crucial: only legitimate users should access any part of information they distribute among storage nodes. We use parameterized Markov Decision Processes to model such a class of systems and Probabilistic Model Checking to assess the likelihood of breaking the confidentiality.We showed that a Small Model Theorem can be proven for a specific types of models, preserving PCTL formulae. Finally, we report the result of applying our methodology to feasibly assess the security of existing dispersed cloud storage solutions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/252391 Collegamento a IRIS

2017 On the security of transmissions over fading wiretap channels in realistic conditions
Proc. IEEE ICC '17
Autore/i: Baldi, M.; Senigagliesi, L.; Chiaraluce, F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Transmissions over the wiretap channel have been studied for a long time from the information theory standpoint. This has allowed to assess the secrecy performance against eavesdropping while ensuring reliable transmission towards the legitimate receiver. However, most previous studies rely on a number of assumptions which are far from practical wireless communications, like infinite length codewords, random coding, discrete channels or continuous channels with Gaussian signaling. In this paper, we show how the level of security at the physical layer can be assessed from the information theoretic standpoint while taking into account the constraints of practical transmissions over realistic wireless wiretap channels, i.e., by considering practical codes with finite length, discrete modulation formats and continuous channels with fading. For this purpose, we consider the notion of mutual information security, which is provably equivalent to semantic security. Our target is to show that classical and already implemented coding and modulation schemes can be used to achieve some level of security at the physical layer, opposed to approaches resorting to completely new designs tailored to secure transmissions. To corroborate this thesis, we consider some coding and modulation schemes compliant with the IEEE 802.16e (WiMax) standard and show how they can be used to achieve some given security level.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/248284 Collegamento a IRIS

2017 On the Error Probability of Short Concatenated Polar and Cyclic Codes with Interleaving
Proc. IEEE ISIT 2017
Autore/i: Ricciutelli, Giacomo; Baldi, Marco; Chiaraluce, Franco; Liva, Gianluigi
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper, we study of the performance of the concatenation of a short polar code with an outer binary linear block code from a distance spectrum viewpoint. Our analysis targets the case where an outer cyclic code is employed together with an inner systematic polar code. A concatenated code ensemble is defined placing an interleaver at the input of the polar encoder. The introduced ensemble allows deriving bounds on the achievable error rates under maximum likelihood decoding, by applying the union bound to the (expurgated) average weight enumerators. The analysis suggests the need of careful optimization of the outer code, to attain low error floors. We also investigate the performance of a number of randomly chosen interleavers, with the aim to discuss the dispersion around the ensemble.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/249743 Collegamento a IRIS

2017 Fondamenti di crittografia
Lavorare con i Big Data. La guida completa per il Data Scientist.
Autore/i: Chiaraluce, F.
Editore: Tecniche Nuove
Luogo di pubblicazione: Milano
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/248446 Collegamento a IRIS

2017 Crittografia simmetrica
Lavorare con i Big Data. La guida completa per il Data Scientist.
Autore/i: Chiaraluce, F.
Editore: Tecniche Nuove
Luogo di pubblicazione: Milano
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/248448 Collegamento a IRIS

2017 State-of-the-Art Space Mission Telecommand Receivers
IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE
Autore/i: Baldi, M.; Bertinelli, M.; Chiaraluce, F.; Closas, P.; Dhakal, P.; Garello, R.; Maturo, N.; Navarro, M.; Palomo, J. M.; Paolini, E.; Pfletschinger, S.; Silva, P. F.; Simone, L.; Vilà-Valls, J.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/250457 Collegamento a IRIS

2017 Certificate validation through public ledgers and blockchains
Proc. ITASEC17
Autore/i: Baldi, M.; Chiaraluce, F.; Frontoni, E.; Spalazzi, L.; Gottardi, G.; Sciarroni, D.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Public key infrastructures (PKIs) are of crucial importance for the life of online services relying on certificate-based authentication, like e-commerce, e-government, online banking, as well as e-mail, social networking, cloud services and many others. One of the main points of failure (POFs) of modern PKIs concerns reliability and security of certificate revocation lists (CRLs), that must be available and authentic any time a certificate is used. Classically, the CRL for a set of certificates is maintained by the same (and sole) certification authority (CA) that issued the certificates, and this introduces a single POF in the system. We address this issue by proposing a solution in which multiple CAs share a public, decentralized and robust ledger where CRLs are collected. For this purpose, we consider the model of public ledgers based on blockchains, introduced for the use in cryptocurrencies, that is becoming a widespread solution for many online applications with stringent security and reliability requirements.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/246067 Collegamento a IRIS

2017 Fondamenti di teoria dell'informazione
Lavorare con i Big Data. La guida completa per il Data Scientist.
Autore/i: Chiaraluce, F.
Editore: Tecniche Nuove
Luogo di pubblicazione: Milano
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/248445 Collegamento a IRIS

2017 Improving deep space telecommunications during solar superior conjunctions
Proc. 38th IEEE Aerospace Conference
Autore/i: Baldi, M.; Chiaraluce, F.; Maturo, N.; Ricciutelli, G.; Finocchiaro, S.; Ardito, A.; , Barbaglio, F.; Simone, L.; Abellò, R.; de Vicente, J.; Mercolino, M.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We discuss the results achieved so far in the RESCUe (Reliable TT&C During Superior Solar Conjunctions) project, funded by the European Space Agency (ESA), whose goal is improving the reliability and capacity of radio links near superior conjunctions, i.e., in the presence of phase and amplitude scintillation due to solar wind and solar corona. The study focuses on the current architecture’s, as well as new technical solutions’, performances in terms of Bit Error Rate (BER) and Codeword Error Rate (CER), especially in the region of Sun-Earth-Probe (SEP) below 5 degrees.This paper presents the analysis of data from Mars Express, in 2013 and 2015, and Cassini, in 2001 and 2002, acquired during solar superior conjunctions. The data analysis allowed to confirm the Rician model for the amplitude fading, and to compute the power spectrum of the phases introduced by plasma for different frequency bands and SEP angles. Such models have been accommodated into an end-to-end software, named ENd-To-end Radio link Simulator Tool (ENTRuST), replicating the telecommand (TC) and telemetry (TM) reception capabilities of a deep space spacecraft and ground station. Link performance has been characterized for nominal link budget (using baseband models) and contingency scenarios (using ENTRuST) at low SEP angles. In the latter case in particular, solar plasma effects impact severely on the link. Technical solutions, in several domains, to mitigate the impact of plasma scintillation and to improve the radio link performance, are proposed and currently being studied. In particular: a) coding techniques, by using Low-Density Parity-Check (LDPC) codes, both in uplink - namely the LDPC(128, 64) code and the LDPC(512, 256) code, and in downlink – namely the LDPC(32768, 16384) code; b) non-coherent modulation schemes, like Frequency Shift Keying (FSK) and Differentially Encoded Phase Shift Keying (DPSK), as an alternative to coherent modulation schemes, like Phase Shift Keying (PSK); c) diversity techniques (space, time and frequency).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/246007 Collegamento a IRIS

2017 A probabilistic small model theorem to assess confidentiality of dispersed cloud storage
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) - 14th International Conference on Quantitative Evaluation of Systems, QEST 2017
Autore/i: Baldi, Marco; Bartocci, Ezio; Chiaraluce, Franco; Cucchiarelli, Alessandro; Senigagliesi, Linda; Spalazzi, Luca; Spegni, Francesco
Editore: Springer Verlag
Classificazione: 2 Contributo in Volume
Abstract: Recent developments in cloud architectures have originated new models of online storage clouds based on data dispersal algorithms. According to these algorithms the data is divided into several slices that are distributed among remote and independent storage nodes. Ensuring confidentiality in this context is crucial: only legitimate users should access any part of information they distribute among storage nodes. To the best of our knowledge, the security analysis and assessment of existing solutions always assumes of homogeneous networks and honestbut-curious nodes as attacker model.We analyze more complex scenarios with heterogeneous network topologies and a passive attacker eavesdropping the channel between user and storage nodes. We use parameterized Markov Decision Processes to model such a class of systems and Probabilistic Model Checking to assess the likelihood of breaking the confidentiality. Even if, generally speaking, the parameterized model checking is undecidable, in this paper, however, we proved a Small Model Theorem that makes such a problem decidable for the class of models adopted in this work. We discovered that confidentiality is highly affected by parameters such as the number of slices and the number of write and read requests. At design-time, the presented methodology helps to determine the optimal values of parameters affecting the likelihood of a successful attack to confidentiality.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/250578 Collegamento a IRIS

2017 Security in heterogeneous distributed storage systems: a practically achievable information-theoretic approach
Proc. ISCC 2017
Autore/i: Baldi, M.; Chiaraluce, F.; Senigagliesi, L.; Spalazzi, L.; Spegni, F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Distributed storage systems and caching systems are becoming widespread, and this motivates the increasing interest on assessing their achievable performance in terms of reliability for legitimate users and security against malicious users. While the assessment of reliability takes benefit of the availability of well established metrics and tools, assessing security is more challenging. The classical cryptographic approach aims at estimating the computational effort for an attacker to break the system, and ensuring that it is far above any feasible amount. This has the limitation of depending on attack algorithms and advances in computing power. The information-theoretic approach instead exploits capacity measures to achieve unconditional security against attackers, but often does not provide practical recipes to reach such a condition. We propose a mixed cryptographic/information theoretic approach with a twofold goal: estimating the levels of information-theoretic security and defining a practical scheme able to achieve them. In order to find optimal choices of the parameters of the proposed scheme, we exploit an effective probabilistic model checker, which allows us to overcome several limitations of more conventional methods.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/250053 Collegamento a IRIS

2017 A trusted cryptocurrency scheme for secure and verifiable digital transactions
FIRST MONDAY
Autore/i: Baldi, Marco; Chiaraluce, Franco
Classificazione: 1 Contributo su Rivista
Abstract: Decentralized digital currency systems known as cryptocurrencies are a breakthrough in electronic payments: the absence of a central authority can avoid the risk that a not fully reliable government seizes assets or causes hyperinflation, very small transactions can be made without incurring high costs and transactions can be traced, thus providing a tool to counter laundering and tax evasion. Furthermore, decentralization provides robustness against many attacks. Despite these advantages, cryptocurrencies have still not become mainstream solutions, because of scarce users’ inclination to adopt them as a privileged payment tool. This is mostly due to the absence of a structured form of control, which also prevents from having some credit insurance. Moreover, some present and future attacks, like quantum computer-based attacks, may threaten their security. In this paper we define new technical solutions to allow cryptocurrencies to become trusted tools for secure and verifiable digital transactions, and also for deposits, while preserving decentralization and users’ privacy. Based on a thorough security analysis, a new cryptocurrency model is first defined, exploiting a set of secure and post-quantum cryptographic primitives. Then, a secure supervision and authentication network is designed, which allows to control transactions, while guaranteeing users’ privacy. A robust reputation system for this context is also proposed, which helps to increase users’ trust and to reduce misconduct.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251585 Collegamento a IRIS

2017 Semantic security with practical transmission schemes over fading wiretap channels
ENTROPY
Autore/i: Senigagliesi, Linda; Baldi, Marco; Chiaraluce, Franco
Classificazione: 1 Contributo su Rivista
Abstract: We propose and assess an on–off protocol for communication over wireless wiretap channels with security at the physical layer. By taking advantage of suitable cryptographic primitives, the protocol we propose allows two legitimate parties to exchange confidential messages with some chosen level of semantic security against passive eavesdroppers, and without needing either pre-shared secret keys or public keys. The proposed method leverages the noisy and fading nature of the channel and exploits coding and all-or-nothing transforms to achieve the desired level of semantic security. We show that the use of fake packets in place of skipped transmissions during low channel quality periods yields significant advantages in terms of time needed to complete transmission of a secret message. Numerical examples are provided considering coding and modulation schemes included in the WiMax standard, thus showing that the proposed approach is feasible even with existing practical devices.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/250782 Collegamento a IRIS

2017 On non-linear codes correcting errors of limited size
Proc. IEEE Globecom 2017
Autore/i: Battaglioni, Massimo; Chiaraluce, Franco; Klove, Torleiv
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The writing operation of multi-level flash memories can suffer from voltage overshoots, which can be generally modeled as asymmetric errors of limited magnitude. Using suitable error correcting codes, these kinds of errors can be corrected. In particular, -ary non-linear codes of length 2 are equivalent to packings of the plane modulo with quasi-crosses. The design procedures for a number of such packings are presented.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/252232 Collegamento a IRIS

2016 Enhanced Public Key Security for the McEliece Cryptosystem
JOURNAL OF CRYPTOLOGY
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Rosenthal J.; Schipani D.
Classificazione: 1 Contributo su Rivista
Abstract: This paper studies a variant of the McEliece cryptosystem able to ensure that the code used as the public key is no longer permutation equivalent to the secret code. This increases the security level of the public key, thus opening the way for reconsidering the adoption of classical families of codes, like Reed–Solomon codes, that have been longly excluded from the McEliece cryptosystem for security reasons. It is well known that codes of these classes are able to yield a reduction in the key size or, equivalently, an increased level of security against information set decoding; so, these are the main advantages of the proposed solution.We also describe possible vulnerabilities and attacks related to the considered system and show what design choices are best suited to avoid them.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/181322 Collegamento a IRIS

2016 Soft McEliece: MDPC code-based McEliece cryptosystem with very compact keys through real-valued intentional errors
Proc. IEEE ISIT 2016
Autore/i: Baldi, Marco; Santini, Paolo; Chiaraluce, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We propose to use real-valued errors instead of classical bit flipping intentional errors in the McEliece cryptosystem based on moderate-density parity-check (MDPC) codes. This allows to exploit the error correcting capability of these codes to the utmost, by using soft-decision iterative decoding algorithms instead of hard-decision bit flipping decoders. However, soft reliability values resulting from the use of real-valued noise can also be exploited by attackers. We devise new attack procedures aimed at this, and compute the relevant work factors and security levels. We show that, for a fixed security level, these new systems achieve the shortest public key sizes ever reached, with a reduction up to 25% with respect to previous proposals.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236145 Collegamento a IRIS

2016 Time-invariant spatially coupled low-density parity-check codes with small constraint length
Proc. IEEE BlackSeaCom 2016
Autore/i: Baldi, M.; Battaglioni, M.; Chiaraluce, F.; Cancellieri, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We consider a special family of spatially coupled low-density parity-check (SC-LDPC) codes, that is, time-invariant low-density parity-check convolutional (LDPCC) codes, which are known in the literature for a long time. Codes of this kind are usually designed by starting from quasi-cyclic (QC) block codes, and applying suitable unwrapping procedures. We show that, by directly designing the LDPCC code syndrome former matrix without the constraints of the underlying QC block code, it is possible to achieve smaller constraint lengths with respect to the best solutions available in the literature. We also find theoretical lower bounds on the syndrome former constraint length for codes with a specified minimum length of the local cycles in their Tanner graphs. For this purpose, we exploit a new approach based on a numerical representation of the syndrome former matrix, which generalizes over a technique we already used to study a special subclass of the codes here considered.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/246529 Collegamento a IRIS

2016 Achieving semantic security without keys through coding and all-or-nothing transforms over wireless channels
Proc. GlobalSIP 2016
Autore/i: Baldi, M.; Senigagliesi, L.; Chiaraluce, F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We propose a simple protocol which allows two legitimate parties to exchange some confidential message over a wireless channel with some chosen level of semantic security against passive eavesdroppers, and without needing either secret or public keys. The proposed method leverages the noisy and fading nature of the channel and exploits coding and all-or-nothing transforms to achieve the desired level of semantic security. We also define suitable metrics to estimate the semantic security level in the considered setting.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/241815 Collegamento a IRIS

2016 Coding for space telemetry and telecommand transmissions in presence of solar scintillation
Proc. TTC 2016
Autore/i: Baldi, M.; Chiaraluce, F.; Maturo, N.; Ricciutelli, G.; Abelló, R.; De Vicente, J.; Mercolino, M.; Ardito, A.; Barbaglio, F.; Finocchiaro, S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We discuss some of the results achieved in the RESCUe project, funded by the European Space Agency, whose goal is improving the reliability and capacity of radio links near superior conjunctions, i.e., in the presence of phase and amplitude scintillation due to solar wind and solar corona. In this paper, in particular, the focus is on the error correcting codes that can be used to maintain acceptable values of the signal-to-noise ratio to achieve prefixed error rate targets, even in the presence of very unfavorable propagation conditions. Both the cases of telemetry and telecommand are considered. We report several numerical results, and propose a procedure to finalize the design in order to determine the maximum data rates achievable.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/245025 Collegamento a IRIS

2016 Performance analysis of transmission over AWGN wiretap channels with practical codes
Physical and Data-Link Security Techniques for Future Communication Systems
Autore/i: Baldi, M.; Chiaraluce, F.; Maturo, N.; Tomasin, S.
Editore: Springer International Publishing
Luogo di pubblicazione: Heidelberg
Classificazione: 2 Contributo in Volume
Abstract: The wiretap coding problem has been addressed since a long time from an information theoretic standpoint. This has permitted to find the ultimate achievable limits under the hypothesis of random coding, which however is far from practice. Some families of practical codes have also been already considered in this scenario, but their achievable secrecy has mostly been assessed in asymptotic conditions (i.e., under the hypothesis of infinite codeword length) and using discrete channel models. In this chapter, we analyze the performance of practical codes over the Gaussian wiretap channel by using suitable metrics which take into account the codeword length and even the specific code structure. This way, we are able to assess the performance of real codes in the finite code length regime, and compare it with the ultimate achievable limits. We focus on low-density parity-check codes as they are among the most viable candidates for the use in this setting.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227926 Collegamento a IRIS

2016 NEXCODE: Next generation uplink coding techniques
Proc. TTC 2016
Autore/i: Baldi, M.; Bertinelli, M.; Chiaraluce, F.; Closas, P.; Garello, R.; Maturo, N.; Navarro, M.; Palomo, J. M.; Paolini, E.; Pfletschinger, S.; Silva, P. F.; Simone, L.; Vilà-Valls, J.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: NEXCODE is a project promoted by the European Space Agency, aimed at research, design, development, and demonstration of a receiver chain for telecommand links in space missions, including the presence of new short low-density parity-check codes for error correction. These codes have excellent performance from the error rate viewpoint but also put new challenges as regards synchronization issues and implementation. In this paper, after a short review of the results obtained through numerical simulations, we present an overview of the breadboard designed for practical testing and the test-plan proposed for the verification of the breadboard and the validation of the new codes and novel synchronization techniques under relevant operation conditions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/245024 Collegamento a IRIS

2016 On the error detection capability of combined LDPC and CRC codes for space telecommand transmissions
Proc. 21st IEEE Symposium on Computer and Communications
Autore/i: Baldi, Marco; Maturo, Nicola; Ricciutelli, Giacomo; Chiaraluce, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We present a method for estimating the undetected error rate when a cyclic redundancy check (CRC) is performed on the output of the decoder of short low-density parity-check (LDPC) codes. This system is of interest for telecommand links, where new LDPC codes have been designed for updating the current standard. We show that these new LDPC codes combined with CRC are adequate for complying with the stringent requirements of this kind of transmissions in terms of error detection.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236007 Collegamento a IRIS

2016 On the use of ordered statistics decoders for low-density parity-check codes in space telecommand links
EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING
Autore/i: Baldi, M.; Maturo, N.; Paolini, E.; Chiaraluce, F.
Classificazione: 1 Contributo su Rivista
Abstract: The performance of short low-density parity-check (LDPC) codes that will be included in the standard for next-generation space telecommanding is analyzed. The paper is focused on the use of a famous ordered statistics decoder known as most reliable basis (MRB) algorithm. Despite its complexity may appear prohibitive in space applications, this algorithm is shown to actually represent a realistic option for short LDPC codes, enabling significant gains over more conventional iterative algorithms. This is possible by a hybrid approach which combines the MRB decoder with an iterative decoding procedure in a sequential manner. The effect of quantization is also addressed, by considering two different quantization laws and comparing their performance. Finally, the impact of limited memory availability onboard of spacecrafts is analyzed and some solutions are proposed for efficient processing, towards a practical onboard decoder implementation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/241228 Collegamento a IRIS

2015 Analysis and performance evaluation of new coding options for space telecommand links - Part I: AWGN channels
INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING
Autore/i: Baldi M.; Chiaraluce F.; Garello R.; Maturo N.; Aguilar Sanchez I.; Cioni S.
Classificazione: 1 Contributo su Rivista
Abstract: We investigate and compare, over the additive white Gaussian noise channel, different options for updating the error correcting code currently used in space mission telecommand links. Besides some more consolidated proposals, using low-density parity-check codes, we characterize and assess the performance of alternative schemes, based on parallel turbo codes and soft-decision decoded Bose-Chaudhuri-Hocquenghem (BCH) codes. The analysis considers relevant metrics like the codeword error rate, the frame error rate, and the undetected frame error rate. The considered codes include binary and non-binary low-density parity-check codes, parallel turbo codes and extended BCH codes, with different decoding algorithms. The complexity of the various schemes and possible limits for their application are considered and discussed. Several numerical examples are provided.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/202119 Collegamento a IRIS

2015 Non-invasive UWB sensing of astronauts’ breathing activity
SENSORS
Autore/i: Baldi M.; Cerri G.; Chiaraluce F.; Eusebi L.; Russo P.
Classificazione: 1 Contributo su Rivista
Abstract: The use of a UWB system for sensing breathing activity of astronauts must account for many critical issues specific to the space environment. The aim of this paper is twofold. The first concerns the definition of design constraints about the pulse amplitude and waveform to transmit, as well as the immunity requirements of the receiver. The second issue concerns the assessment of the procedures and the characteristics of the algorithms to use for signal processing to retrieve the breathing frequency and respiration waveform. The algorithm has to work correctly in the presence of surrounding electromagnetic noise due to other sources in the environment. The highly reflecting walls increase the difficulty of the problem and the hostile scenario has to be accurately characterized. Examples of signal processing techniques able to recover breathing frequency in significant and realistic situations are shown and discussed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/204713 Collegamento a IRIS

2015 Method and apparatus for public-key cryptography based on error correcting codes
Autore/i: Baldi, M.; Bianchi, M.; Chiaraluce, F.; Rosenthal, J. J.; Schipani, D. M.
Classificazione: 6 Brevetti
Abstract: Method and apparatus for generating a private-public key pair, for encrypting a message for transmission through an unsecure communication medium, and for decrypting the message are disclosed. The methods are based on the well-known McEliece cryptosystem or on its Niederreiter variant. More general transformation matrices Q are used in place of permutation matrices, possibly together with an appropriate selection of the intentional error vectors. The transformation matrices Q are non-singular nxn matrices having the form Q = R + T, where the matrix R is a rank-z matrix and the matrix T is some other matrix rendering Q non-singular. The new Q matrices, though at least potentially being dense, have a limited propagation effect on the intentional error vectors for the authorized receiver. The use of this kind of matrices allows to better disguise the private key into the public one, without yielding any further error propagation effect. Based on this family of Q matrices, the presently proposed cryptosystem enables the use of different families of codes than Goppa codes, such as RS codes, by ensuring increased public key security.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/250013 Collegamento a IRIS

2015 Security gap analysis of some LDPC coded transmission schemes over the flat and fast fading Gaussian wire-tap channels
EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING
Autore/i: Baldi, M.; Maturo, N.; Ricciutelli, G.; Chiaraluce, F.
Classificazione: 1 Contributo su Rivista
Abstract: It is known that the error rate can be used as a measure of reliability and security over the wire-tap channel when practical, finite length codes are used for transmission, and the security gap is an error rate based metric able to jointly treat these two aspects. In this paper, we consider several low-density parity-check (LDPC) coded transmissions, which represent the state of the art for transmissions over the wire-tap channel and we assess and compare their security gap performance. We consider two kinds of wire-tap channels: the flat and the fast fading wire-tap channels with additive white Gaussian noise. As a reference, we use the progressive edge growth (PEG) algorithm for the design of unstructured LDPC codes and compare its performance with that of four approaches for designing structured LDPC codes. We analyze both systematic and non-systematic transmissions and show that some structured code design techniques are able to achieve comparable or even better performance than the PEG algorithm over the considered channels, while taking advantage of their simpler encoding and decoding procedures.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/228043 Collegamento a IRIS

2015 A modification of the McEliece cryptosystem based on Generalized Reed-Solomon codes
Book of Abstracts MEGA 2015 – Effective Methods in Algebraic Geometry
Autore/i: Baldi, M.; Chiaraluce, F.; Rosenthal, J.; Schipani, D.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/226943 Collegamento a IRIS

2015 Performance assessment and design of finite length LDPC codes for the Gaussian wiretap channel
Proceedings of ICC 2015
Autore/i: Baldi, Marco; Ricciutelli, Giacomo; Maturo, Nicola; Chiaraluce, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this work we study the reliability and secrecy performance achievable by practical low-density parity-check (LDPC) codes over the Gaussian wiretap channel. While several works have already addressed this problem in asymptotic conditions, i.e., under the hypothesis of codewords of infinite length, only a few approaches exist for the finite length regime. We propose an approach to measure the performance of practical codes and compare it with that achievable in asymptotic conditions. Moreover, based on the secrecy metrics we adopt to achieve this target, we propose a code optimization algorithm which allows to design irregular LDPC codes able to approach the ultimate performance limits even at moderately small codeword lengths (in the order of 10000 bits).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/226732 Collegamento a IRIS

2015 LDPC coded modulation schemes with largely unequal error protection
Proc. 2015 IEEE Black Sea Conference on Communications and Networking (BlackSeaCom)
Autore/i: Ricciutelli, G.; Baldi, M.; Maturo, N.; Chiaraluce, F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Coding and modulation schemes able to achieve unequal error protection are of interest for many applications in which parts of the payload must be differently protected against the noise. They are also useful for physical layer security of transmissions over the broadcast channel with confidential messages. Classical design approaches aim at optimizing the performance over all the protection classes, independently of the separation between them. We instead propose a solution to improve the performance over the most protected bits, at the expense of performance over the least protected ones. This allows to design coded modulation schemes with largely unequal error protection. We also consider the use of high order modulations, and propose a technique to study the performance over each protection class in the asymptotic regime of infinite code length.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227615 Collegamento a IRIS

2015 Analysis and performance evaluation of new coding options for space telecommand links – Part II: jamming channels
INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING
Autore/i: Baldi M.; Chiaraluce F.; Garello R.; Maturo N.; Aguilar Sanchez I.; Cioni S.
Classificazione: 1 Contributo su Rivista
Abstract: In this paper, we study the performance of telecommand space links affected by pulsed, continuous wave and pseudo-noise jamming. Countermeasures include coding, interleaving, and direct sequence spread spectrum. Binary and non-binary low-density parity-check codes, parallel turbo codes, and soft-decision decoded BCH codes are considered.We investigate the impact of different decoding algorithms, also taking into account the role of jamming state information, spreading processing gain and interleaving. The results show that significant gains (up to more than 10 dB) can be achieved in a number of interesting scenarios.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/202121 Collegamento a IRIS

2015 On the applicability of the most reliable basis algorithm for LDPC decoding in telecommand links
Proceedings of iCICS 2015
Autore/i: Baldi, Marco; Maturo, Nicola; Paolini, Enrico; Chiaraluce, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We analyze the performance of two short lowdensity parity-check codes recently proposed for updating the telecommand standard for space links. We show that the most reliable basis decoding algorithm can be efficiently applied to these codes, permitting us to achieve a significant coding gain with respect to more conventional iterative algorithms. In particular, in order to maintain limited complexity, we suggest to use a hybrid approach, that combines the two decoding procedures in a sequential manner. Thinking in terms of practical implementation, we also investigate the impact of quantization, by considering two different quantization laws and comparing their performance.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/224850 Collegamento a IRIS

2014 Practical LDPC coded modulation schemes for the fading broadcast channel with confidential messages
Proc. ICC 2014
Autore/i: Baldi M.; Maturo N.; Ricciutelli G.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The broadcast channel with confidential messages is a well studied scenario from the theoretical standpoint, but there is still lack of practical schemes able to achieve some fixed level of reliability and security over such a channel. In this paper, we consider a quasi-static fading channel in which both public and private messages must be sent from the transmitter to the receivers, and we aim at designing suitable coding and modulation schemes to achieve such a target. For this purpose, we adopt the error rate as a metric, by considering that reliability (security) is achieved when a sufficiently low (high) error rate is experienced at the receiving side. We show that some conditions exist on the system feasibility, and that some outage probability must be tolerated to cope with the fading nature of the channel. The proposed solution exploits low-density parity-check codes with unequal error protection, which are able to guarantee two different levels of protection against noise for the public and the private information, in conjunction with different modulation schemes for the public and the private message bits.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/173105 Collegamento a IRIS

2014 Sparse generator matrices for some families of quasi-cyclic low-density parity-check codes
Proc. SoftCOM 2014
Autore/i: Baldi M.; Cancellieri G.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper, we provide a general form for sparse generator matrices of several families of Quasi-Cyclic Low-Density Parity-Check codes. Codes of this kind have a prominent role in literature and applications due to their ability to achieve excellent performance with limited complexity. While some properties of these codes (like the girth length in their associated Tanner graphs) are well investigated, estimating their minimum distance is still an open problem. By obtaining sparse generator matrices for several families of these codes, we prove that they are also Quasi-Cyclic Low-Density Generator Matrix codes, which is an important feature to reduce the encoding complexity, and provides a useful tool for the investigation of their minimum distance.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/187903 Collegamento a IRIS

2014 A hybrid decoding scheme for short non-binary LDPC codes
IEEE COMMUNICATIONS LETTERS
Autore/i: Baldi M.; Chiaraluce F.; Maturo N.; Liva G.; Paolini E.
Classificazione: 1 Contributo su Rivista
Abstract: In this paper, an iterative soft-decision hybrid decoding algorithm for non-binary low-density parity-check (LDPC) codes with short codeword lengths is proposed. The rationale of the approach is to combine the classical belief propagation (BP) iterative LDPC decoding algorithm with the most reliable basis (MRB) decoding algorithm. This allows to achieve significant performance improvements, with a complexity that, for medium/low error rates, is only slightly higher than that of the BP algorithm alone. The performance improvement with respect to pure BP decoding is up to 0.7 dB at codeword error rate (CER) ≈ 10−5. Notably, for a fixed MRB order, hybrid decoding achieves a gain up to 0.5 dB at CER ≈ 10−5 with respect to BP decoding and MRB decoding used alone
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/202923 Collegamento a IRIS

2014 AONT-LT: A data protection scheme for cloud and cooperative storage systems
Proc. HPCS 2014
Autore/i: Baldi M.; Maturo N.; Montali E.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We propose a variant of the well-known AONT-RS scheme for dispersed storage systems. The novelty consists in replacing the Reed-Solomon code with rateless Luby transform codes. The resulting system, named AONT-LT, is able to improve the performance by dispersing the data over an arbitrarily large number of storage nodes while ensuring limited complexity. The proposed solution is particularly suitable in the case of cooperative storage systems. It is shown that while the AONT-RS scheme requires the adoption of fragmentation for achieving widespread distribution, thus penalizing the performance, the new AONT-LT scheme can exploit variable length codes which allow to achieve very good performance and scalability.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/179114 Collegamento a IRIS

2014 LDPC coded transmissions over the Gaussian broadcast channel with confidential messages
Proc. ICT 2014
Autore/i: Baldi M.; Maturo N.; Ricciutelli G.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We design and assess some practical low-density parity-check (LDPC) coded transmission schemes for the Gaussian broadcast channel with confidential messages (BCC). This channel model is different from the classical wiretap channel model as the unauthorized receiver (Eve) must be able to decode some part of the information. Hence, the reliability and security targets are different from those of the wiretap channel. In order to design and assess practical coding schemes, we use the error rate as a metric of the performance achieved by the authorized receiver (Bob) and the unauthorized receiver (Eve). We study the system feasibility, and show that two different levels of protection against noise are required on the public and the secret messages. This can be achieved in two ways: i) by using LDPC codes with unequal error protection (UEP) of the transmitted information bits or ii) by using two classical non-UEP LDPC codes with different rates. We compare these two approaches and show that, for the considered examples, the solution exploiting UEP LDPC codes is more efficient than that using non-UEP LDPC codes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/166902 Collegamento a IRIS

2014 Error correcting codes in telecommand and telemetry for European Space Agency missions: An overview and new perspectives
Proc. SoftCOM 2014
Autore/i: Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Error correcting codes have always played a prominent role in the definition of secure and reliable space missions. Both telecommand (TC) and telemetry (TM) have benefited by the introduction of suitable co/decoding schemes, ranging from classic Bose-Chaudhuri-Hocquenghem, Reed-Solomon and convolutional codes to more recent state-of-the art codes based on soft-decision and iterative decoding. As a matter of fact, space TM was one of the first scenarios to propose implementation of the concept of turbo coding that, since twenty years, has traced a new paradigm in the field of error correction. At present the scene is dominated by low-density parity-check codes and these are being progressively included in the design of future missions, in either deep-space or near-Earth scenarios, for the possibility they offer to increase the data rate and/or to reduce the signal-to-noise ratio. The European Space Agency is very active in the field and continuously gives relevant contributions to the standardization activities within the Consultative Committee for Space Data Systems. This paper provides an overview of the error correcting codes included in the current TC and TM recommendations and discusses the new solutions recently proposed in view of most demanding missions, also able to operate in hostile environments like, for example, in the presence of jamming.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/187902 Collegamento a IRIS

2014 Secrecy transmission on parallel channels: theoretical limits and performance of practical codes
IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY
Autore/i: Baldi M.; Chiaraluce F.; Laurenti N.; Tomasin S.; Renna F.
Classificazione: 1 Contributo su Rivista
Abstract: We consider a system where an agent (Alice) aims at transmitting a message to a second agent (Bob) over a set of parallel channels, while keeping it secret from a third agent (Eve) by using physical layer security techniques. We assume that Alice perfectly knows the set of channels with respect to Bob, but she has only a statistical knowledge of the channels with respect to Eve. We derive bounds on the achievable outage secrecy rates, by considering coding either within each channel or across all parallel channels. Transmit power is adapted to the channel conditions, with a constraint on the average power over the whole transmission. We also focus on the maximum cumulative outage secrecy rate that can be achieved. Moreover, in order to assess the performance in a real life scenario, we consider the use of practical error correcting codes. We extend the definitions of security gap and equivocation rate, previously applied to the single additive white Gaussian noise channel, to Rayleigh distributed parallel channels, on the basis of the error rate targets and the outage probability. Bounds on these metrics are also derived, considering the statistics of the parallel channels. Numerical results are provided, that confirm the feasibility of the considered physical layer security techniques.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/189507 Collegamento a IRIS

2014 Array Convolutional Low-Density Parity-Check Codes
IEEE COMMUNICATIONS LETTERS
Autore/i: Baldi, M.; Cancellieri, G.; Chiaraluce, F.
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents a design technique for obtaining regular time-invariant low-density parity-check convolutional (RTI-LDPCC) codes with low complexity and good performance. We start from previous approaches which unwrap a low-density parity-check (LDPC) block code into an RTI-LDPCC code, and we obtain a new method to design RTI-LDPCC codes with better performance and shorter constraint length. Differently from previous techniques, we start the design from an array LDPC block code. We show that, for codes with high rate, a performance gain and a reduction in the constraint length are achieved with respect to previous proposals. Additionally, an increase in the minimum distance is observed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/147904 Collegamento a IRIS

2013 Security and complexity of the McEliece cryptosystem based on quasi-cyclic low-density parity-check codes
IET INFORMATION SECURITY
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.
Classificazione: 1 Contributo su Rivista
Abstract: In the context of public key cryptography, the McEliece cryptosystem represents a very smart solution based on the hardness of the decoding problem, which is believed to be able to resist the advent of quantum computers. Despite this, the original McEliece cryptosystem based on Goppa codes, has encountered limited interest in practical applications, partly because of some constraints imposed by this very special class of codes. The authors have recently introduced a variant of the McEliece cryptosystem including low-density parity-check codes, that are state-of-the-art codes, now used in many telecommunication standards and applications. In this study, the authors discuss the possible use of a bit-flipping decoder in this context, which gives a significant advantage in terms of complexity. The authors also provide theoretical arguments and practical tools for estimating the trade-off between security and complexity, in such a way to give a simple procedure for the system design.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110869 Collegamento a IRIS

2013 A practical viewpoint on the performance of LDPC codes over the fast Rayleigh fading wire-tap channel
Proc. ISCC’13
Autore/i: Baldi M.; Bianchi M.; Maturo N.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110874 Collegamento a IRIS

2013 Advanced coding schemes against jamming in telecommand links
Proc. Milcom 2013
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Garello R.; Maturo N.; Aguilar Sanchez I.; Cioni S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The aim of this paper is to study the performance of some coding schemes recently proposed for updating the TC channel coding standard for space applications, in the presence of jamming. Besides low-density parity-check codes, that appear as the most eligible candidates, we also consider other solutions based on parallel turbo codes and extended BCH codes. We show that all these schemes offer very good performance, which approaches the theoretical limits achievable.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/134662 Collegamento a IRIS

2013 Security gap assessment for the fast fading wiretap channel
Proc. ICT 2013
Autore/i: Maturo N.; Baldi M.; Bianchi M.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110867 Collegamento a IRIS

2013 Using LDGM codes and sparse syndromes to achieve digital signatures
Post-Quantum Cryptography
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Rosenthal J.; Schipani D.
Editore: Springer-Verlag
Luogo di pubblicazione: Berlin Heidelberg
Classificazione: 2 Contributo in Volume
Abstract: In this paper, we address the problem of achieving efficient code-based digital signatures with small public keys. The solution we propose exploits sparse syndromes and randomly designed low-density generator matrix codes. Based on our evaluations, the proposed scheme is able to outperform existing solutions, permitting to achieve considerable security levels with very small public keys.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110868 Collegamento a IRIS

2013 A tight estimation of the security gap over the fast fading wiretap channel
Proc. IWCMC 2013
Autore/i: Baldi M.; Bianchi M.; Maturo N.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110871 Collegamento a IRIS

2013 Optimization of the parity-check matrix density in QC-LDPC code-based McEliece cryptosystems
Proc. IEEE ICC'13
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110870 Collegamento a IRIS

2013 Security gap performance of some LDPC code constructions
Proc. TSP 2013
Autore/i: Maturo N.; Baldi M.; Bianchi M.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110872 Collegamento a IRIS

2013 Advanced channel coding for space mission telecommand links
Proc. VTC2013-Fall
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Garello R.; Aguilar Sanchez I.; Cioni S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/114462 Collegamento a IRIS

2013 A physical layer secured key distribution technique for IEEE 802.11g wireless networks
IEEE WIRELESS COMMUNICATIONS LETTERS
Autore/i: Baldi M.; Bianchi M.; Maturo N.; Chiaraluce F.
Classificazione: 1 Contributo su Rivista
Abstract: Key distribution and renewing in wireless local area networks is a crucial issue to guarantee that unauthorized users are prevented from accessing the network. In this paper, we propose a technique for allowing an automatic bootstrap and periodic renewing of the network key by exploiting physical layer security principles, that is, the inherent differences among transmission channels. The proposed technique is based on scrambling of groups of consecutive packets and does not need the use of an initial authentication nor automatic repeat request protocols. We present a modification of the scrambling circuits included in the IEEE 802.11g standard which allows for a suitable error propagation at the unauthorized receiver, thus achieving physical layer security.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/99262 Collegamento a IRIS

2013 Channel coding schemes protection against jamming for direct sequence spread spectrum telecommand links
Proc. TTC 2013
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Garello R.; Aguilar Sanchez I.; Cioni S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/120263 Collegamento a IRIS

2013 Low-power secret-key agreement over OFDM
Proceedings ACM HotWiSec 2013
Autore/i: Renna F.; Laurenti N.; Tomasin S; . Baldi M.; Maturo N.; Bianchi M.; Chiaraluce F.; Bloch M.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/96862 Collegamento a IRIS

2013 Design, performance evaluation and comparison of turbo codes and BCH codes for telecommand applications
Proc. TTC 2013
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Garello R.; Aguilar Sanchez I.; Cioni S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/120262 Collegamento a IRIS

2013 Improving the efficiency of the LDPC code-based McEliece cryptosystem through irregular codes
Proc. ISCC’13
Autore/i: Baldi M.; Bianchi M.; Maturo N.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/110873 Collegamento a IRIS

2012 Body Movement Compensation in UWB Radars for Respiration Monitoring
Proceedings 2012 Estel Conference
Autore/i: Baldi M.; Appignani F.; Zanaj B.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper deals with the application of UWB radars for detecting the respiration parameters of a human being. We demonstrate that a simple algorithm used in the case of still subjects can be adapted, with small modifications, to the case in which the subject is moving. The algorithm can be applied to the relevant scenario of monitoring the respiration activity of an astronaut during rest.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/81823 Collegamento a IRIS

2012 A class of punctured simplex codes which are proper for error detection
IEEE TRANSACTIONS ON INFORMATION THEORY
Autore/i: M. Baldi; M. Bianchi; F. Chiaraluce; T. Kløve
Classificazione: 1 Contributo su Rivista
Abstract: Binary linear [n, k] codes that are proper for error detection are known for many combinations of n and k. For the remaining combinations, existence of proper codes is conjectured. In this paper, a particular class of [n, k] codes is studied in detail. In particular, it is shown that these codes are proper for many combinations of n and k which were previously unsettled.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/69653 Collegamento a IRIS

2012 Interleaved product LDPC codes
IEEE TRANSACTIONS ON COMMUNICATIONS
Autore/i: M. Baldi; G. Cancellieri; F. Chiaraluce
Classificazione: 1 Contributo su Rivista
Abstract: Product LDPC codes take advantage of LDPC decoding algorithms and the high minimum distance of product codes. We propose to add suitable interleavers to improve the waterfall performance of LDPC decoding. Interleaving also reduces the number of low weight codewords, that gives a further advantage in the error floor region.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/69651 Collegamento a IRIS

2012 Security and complexity of the McEliece cryptosystem based on QC-LDPC codes
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.
Classificazione: 5 Altro
Abstract: Riunione GTTI 2012, Sessione on Transmission
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/73513 Collegamento a IRIS

2012 On the generator matrix of array LDPC codes
Proc. SoftCOM 2012
Autore/i: Baldi M.; Bianchi M.; Cancellieri G.; Chiaraluce F.; Kløve T.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80364 Collegamento a IRIS

2012 Progressive differences convolutional low-density parity-check codes
IEEE COMMUNICATIONS LETTERS
Autore/i: Baldi M.; Bianchi M.; Cancellieri G.; Chiaraluce F.
Classificazione: 1 Contributo su Rivista
Abstract: We present a new family of low-density paritycheck (LDPC) convolutional codes that can be designed using ordered sets of progressive differences. We study their properties and define a subset of codes in this class that have some desirable features, such as fixed minimum distance and Tanner graphs without short cycles. The design approach we propose ensures that these properties are guaranteed independently of the code rate. This makes these codes of interest in many practical applications, particularly when high rate codes are needed for saving bandwidth.We provide some examples of coded transmission schemes exploiting this new class of codes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80758 Collegamento a IRIS

2012 A comparison between APSK and QAM in wireless tactical scenarios for land mobile systems
EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING
Autore/i: Baldi M; Chiaraluce F.; de Angelis A.; Marchesani R.; Schillaci S.
Classificazione: 1 Contributo su Rivista
Abstract: We evaluate the performance of APSK modulation for wireless systems and compare it with the performance of more conventional QAM systems. In previous literature, the analysis of APSK has been mainly focused on the AWGN channel. This channel model provides useful insights when APSK is used in satellite systems, while it is important to consider more complex channel models for its use in terrestrial wireless applications. In particular, we consider wireless tactical scenarios for land mobile systems, that are of interest for military applications, and provide several numerical examples. First, we explore the effects on the total degradation of the reduced PAPR, typical of APSK, also taking into account the nonlinearity of HPAs and the need to use adaptive predistortion. Then, the bit error rate performance is assessed by simulation, for some typical multipath scenarios with decision feedback equalization, also including the presence of turbo channel coding. Our analysis shows that APSK can be a valid alternative to QAM in all cases in which the nonlinear effects due to HPAs cannot be neglected.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/81382 Collegamento a IRIS

2012 Coding with scrambling, concatenation, and HARQ for the AWGN wire-tap channel: a security gap analysis
IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY
Autore/i: M. Baldi; M. Bianchi; F. Chiaraluce
Classificazione: 1 Contributo su Rivista
Abstract: This paper examines the use of nonsystematic channel codes to obtain secure transmissions over the additive white Gaussian noise wire-tap channel. Unlike the previous approaches, we propose to implement nonsystematic coded transmission by scrambling the information bits, and characterize the bit error rate of scrambled transmissions through theoretical arguments and numerical simulations. We have focused on some examples of Bose-Chaudhuri-Hocquenghem and low-density parity-check codes to estimate the security gap, which we have used as a measure of physical layer security, in addition to the bit error rate. Based on a number of numerical examples, we found that such a transmission technique can outperform alternative solutions. In fact, when an eavesdropper (Eve) has a worse channel than the authorized user (Bob), the security gap required to reach a given level of security is very small. The amount of degradation of Eve’s channel with respect to Bob’s that is needed to achieve sufficient security can be further reduced by implementing scrambling and descrambling operations on blocks of frames, rather than on single frames. While Eve’s channel has a quality equal to or better than that of Bob’s channel, we have shown that the use of a hybrid automatic repeat-request protocol with authentication still allows achieving a sufficient level of security. Finally, the secrecy performance of some practical schemes has also been measured in terms of the equivocation rate about the message at the eavesdropper and compared with that of ideal codes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/69652 Collegamento a IRIS

2011 Analysis and simulation of algorithms for vital sign detection using UWB radars
Proc. ICUWB 2011
Autore/i: Baldi M.; Chiaraluce F.; Zanaj B.; Moretti M.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62354 Collegamento a IRIS

2011 Analytical evaluation of the role of estimation and quantization errors in downstream vectored VDSL systems
INTERNATIONAL JOURNAL ON ADVANCES IN TELECOMMUNICATIONS
Autore/i: Baldi M.; Chiaraluce F.; Garello R.; Polano M.; Valentini M.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62353 Collegamento a IRIS

2011 Performance evaluation of some distributed averaging algorithms for sensor networks
INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS
Autore/i: Baldi M.; Zanaj E.; Chiaraluce F.
Classificazione: 1 Contributo su Rivista
Abstract: Though capillary sensor networks have the advantage of reporting punctual estimations of their sensed quantity, it is often useful for the nodes to know the overall average value of the same quantity. This is required, for example, when the network can make autonomous decisions. Several algorithms exist for solving the averaging problem in a distributed manner. Their efficiency can be measured by the number of iterations needed to converge to the average sensed value. In this paper, we consider two point-topoint and one point-to-multipoint distributed averaging algorithms that can be seen as variants of the same averaging solution. We define a set of analytical tools to evaluate the performance of these algorithms and to optimize their parameters in such a way to accelerate convergence.We also provide a performance assessment, based on numerical simulations, aimed at verifying the results of the analytical treatment and at comparing the considered schemes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62956 Collegamento a IRIS

2011 Signal modeling and processing for physiological sensing through UWB radars
Proc. SoftCOM 2011
Autore/i: Baldi M.; Chiaraluce F.; Moretti M.; Venieri F.; Zanaj B.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62355 Collegamento a IRIS

2011 Increasing physical layer security through scrambled codes and ARQ
Proc. ICC 2011 - Workshop on Physical Layer Security
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/57097 Collegamento a IRIS

2011 On a family of circulant matrices for quasi-cyclic low-density generator matrix codes
IEEE TRANSACTIONS ON INFORMATION THEORY
Autore/i: Baldi M.; Bambozzi F.; Chiaraluce F.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/61700 Collegamento a IRIS

2011 On fuzzy syndrome hashing with LDPC coding
Proc. ISABEL 2011
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Rosenthal J.; Schipani D.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63601 Collegamento a IRIS

2011 A variant of the McEliece cryptosystem with increased public key security
Proc. Seventh International Workshop on Coding and Cryptography (WCC 2011)
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Rosenthal J.; Schipani D.
Luogo di pubblicazione: Paris, France
Classificazione: 5 Altro
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63602 Collegamento a IRIS

2011 Performance of Gossip Algorithms in Wireless Sensor Networks
Solutions on Embedded Systems
Autore/i: M. BALDI; F. CHIARALUCE; E. ZANAJ
Editore: Springer
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/55707 Collegamento a IRIS

2011 Performance of APSK modulation in wireless tactical scenarios for land mobile systems
Proc. ISCC'11
Autore/i: Baldi M.; Chiaraluce F.; De Angelis A.; Marchesani R.; Schillaci S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/59104 Collegamento a IRIS

2011 Analysis of the correlation coefficient between component noise squared norms for OFDM systems
IEEE SIGNAL PROCESSING LETTERS
Autore/i: N. Rožić; F. Chiaraluce; J. Radić
Classificazione: 1 Contributo su Rivista
Abstract: We present an exact analysis of the correlation coefficient, in the frequency domain, between the real and imaginary parts of the impulse noise squared norms for OFDM systems. We analyze a scenario where M Gaussian randomly positioned impulses interfere the OFDM signal, with and without the presence of a background thermal noise. Variability of M is taken into account through the Bernoulli–Gauss model. We demonstrate that rather high correlation values occur with not negligible probabilities under certain operation conditions. This has an impact on the design of impulse noise suppression techniques as well as on the error rate performance.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/55706 Collegamento a IRIS

2011 Using Blaum-Sanyal codes for error detection
Autore/i: Baldi M.; Bianchi M.; Chiaraluce F.; Kløve T.
Classificazione: 5 Altro
Abstract: Riunione Annuale GTTI 2011, Session on Transmission, Messina-Taormina, June 2011
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/58218 Collegamento a IRIS

2010 Exploiting concatenation in the design of low-density parity-check codes
INTERNATIONAL JOURNAL ON ADVANCES IN TELECOMMUNICATIONS
Autore/i: BALDI M; CANCELLIERI G; F. CHIARALUCE
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/51403 Collegamento a IRIS

2010 Design of permuted serially concatenated multiple parity-check codes
Proc. SoftCOM 2010
Autore/i: BALDI M; G. CANCELLIERI; CHIARALUCE F; DE AMICIS A
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/50599 Collegamento a IRIS

2010 Physical layer security through non-systematic coding
Riunione Annuale GTTI 2010, Session on Trasmission Technologies, Brescia,
Autore/i: BALDI M; BIANCHI M; F. CHIARALUCE
Classificazione: 5 Altro
Abstract: Riunione Annuale GTTI 2010, Session on Transmission Technologies
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/49645 Collegamento a IRIS

2010 Regular and irregular multiple serially-concatenated multiple-parity-check codes for wireless applications
JOURNAL OF COMMUNICATION SOFTWARE AND SYSTEMS
Autore/i: BALDI M; CANCELLIERI G; CHIARALUCE F; DE AMICIS A
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/50480 Collegamento a IRIS

2010 Irregular M-SC-MPC codes for wireless applications
Proc. European Wireless 2010
Autore/i: BALDI M; CANCELLIERI G; F. CHIARALUCE; DE AMICIS A
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/47266 Collegamento a IRIS

2010 On the autocorrelation properties of truncated maximum-length sequences and their effect on the power spectrum
IEEE TRANSACTIONS ON SIGNAL PROCESSING
Autore/i: BALDI M; F. CHIARALUCE; BOUJNAH N; GARELLO R
Classificazione: 1 Contributo su Rivista
Abstract: Truncated maximum-length binary sequences are studied in this paper. The impact of truncation on their autocorrelation properties and power spectral density is investigated. Several new analytical results are given and validated through simulation. The first- and second-order statistics of the periodic autocorrelation function and the spectral peak amplitudes over the ensemble of all possible starting seeds are analyzed. Explicit bounds are found for the mean square of the periodic autocorrelation function. An analytical technique for evaluating the maximum spectral peak values is derived. As a case study, high data rate space links using LFSR randomizers are considered. Truncation may induce high peaks in the spectrum, requiring suitable margins to comply with power flux density constraints. The new results allow to analytically estimate the margin, providing useful information for the link design.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/34396 Collegamento a IRIS

2010 Non-systematic codes for physical layer security
Proceedings ITW 2010
Autore/i: BALDI M; BIANCHI M; F. CHIARALUCE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/47268 Collegamento a IRIS

2010 Simple statistical analysis of the impact of some nonidealities in downstream VDSL with linear precoding
EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING
Autore/i: BALDI M; F. CHIARALUCE; GARELLO R; POLANO M; VALENTINI M
Editore: Cairo: Hindawi Publishing Corporation
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/34945 Collegamento a IRIS

2010 On the effect of estimation and quantization errors in downstream VDSL systems
Proc. CTRQ 2010
Autore/i: BALDI M; F. CHIARALUCE; GARELLO R; POLANO M; VALENTINI M
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/47267 Collegamento a IRIS

2009 Telecommand authentication in space missions: cryptanalysis and future trends
IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS
Autore/i: SPINSANTE S; F. CHIARALUCE; GAMBI E
Classificazione: 1 Contributo su Rivista
Abstract: An algebraic method is outlined to force the European Space Agency (ESA) telecommand (TC) authentication system, and we investigate more robust algorithms, by testing different operational modes of the Advanced Encryption Standard (AES), in conjunction with error correction strategies, already included in space recommendations.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/51517 Collegamento a IRIS

2009 Finite-precision analysis of demappers and decoders for LDPC-coded M-QAM systems
IEEE TRANSACTIONS ON BROADCASTING
Autore/i: BALDI M; CHIARALUCE F; G. CANCELLIERI
Classificazione: 1 Contributo su Rivista
Abstract: LDPC codes are state-of-art error correcting codes, included in several standards for broadcast transmissions. Iterative soft-decision decoding algorithms for LDPC codes reach excellent error correction capability; their performance, however, is strongly affected by finite-precision issues in the representation of inner variables. Great attention has been paid, in recent literature, to the topic of quantization for LDPC decoders, but mostly focusing on binary modulations and analysing finite precision effects in a disaggregrated manner, i.e., considering separately each block of the receiver. Modern telecommunication standards, instead, often adopt high order modulation schemes, e.g. M-QAM, with the aim to achieve large spectral efficiency. This puts additional quantization problems, that have been poorly debated in previous literature. This paper discusses the choice of suitable quantization characteristics for both the decoder messages and the received samples in LDPC-coded systems using M-QAM schemes. The analysis involves also the demapper block, that provides initial likelihood values for the decoder, by relating its quantization strategy with that of the decoder. A new demapper version, based on approximate expressions, is also presented, that introduces a slight deviation from the ideal case but yields a low complexity hardware implementation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/51050 Collegamento a IRIS

2009 A class of low-density parity-check product codes
Proc. SPACOMM 2009
Autore/i: BALDI M; G. CANCELLIERI; CHIARALUCE F
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/52055 Collegamento a IRIS

2009 Impact of truncation on the statistical properties of LFSR sequences
Proc. SCS 2009
Autore/i: M. BALDI; F. CHIARALUCE; N. BOUJNAH; R. GARELLO
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/47265 Collegamento a IRIS

2009 Good LDPC codes based on very simple component codes
Riunione Annuale GTTI 2009 - Session on Trasmission
Autore/i: BALDI M; CANCELLIERI G; F. CHIARALUCE
Classificazione: 5 Altro
Abstract: Riunione Annuale GTTI 2009, Session on Transmission
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/49124 Collegamento a IRIS

2009 Some remarks on the problem of spurious frequencies in high data rate space missions
Proc. 2009 First International Conference on Advances in Satellite and Space Communications
Autore/i: BALDI M; F. CHIARALUCE; CALZOLARI G. P; GARELLO R
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/47261 Collegamento a IRIS


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