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Despite the development of numerous cryptographic algorithms over the last decade to ensure greater security for the users, the cyberattack forms are still advancing, which creates a challenge for the research community to build more efficient infrastructure. It motivates us to design more advanced algorithms based on a set of matrices that form a group under matrix multiplication, meaning they satisfy the group axioms of closure, associativity, identity, and irreversibility. Specifically, this study explores the application of three cryptographic algorithms on a special linear group of matrices over a ring of integers modulo m. The first algorithm relies on the RSA key exchange algorithm, which we modify to a special linear group. The second is an asymmetric RSA variant of a cryptographic algorithm defined on the co-adjoint orbit of element K belonging to a special linear group. All matrices from the orbit of matrix K have the same order and can be easily encrypted and decrypted by a pair of secret asymmetric cryptographic keys. We apply the Kronecker product of non-Abelian groups to construct an energy-efficient cryptographic algorithm with possible application on sensor networks. Due to the multiplicative property of the Kronecker product, both the encryption and decryption can be performed in parallel over the matrices of low degree. The third one is another RSA variant of a symmetric cryptographic algorithm, which can be encoded with a special linear group to significantly increase its complexity at the stage of non-negative matrix factorization. To encrypt a given set of numbers, we write it in a matrix form with a secret sequence of generators. As a result, the decryption relies on solving a simple system of nonlinear equations. Security of the algorithm lies in its complexity, aimed at building a correct sequence of generators necessary for encryption.

This paper proposes a discrete Gaussian sampling hardware design that can flexibly support different sampling parameters, that is more efficient (in area-delay product) compared to the majority of earlier proposals, and that has constant execution time. The proposed design implements a Cumulative Distribution Table (CDT) approach, reduces the table size with Gaussian convolutions, and adopts an innovative fusion tree search algorithm to achieve a compact and fast sampling technique—to our best knowledge, this is the first hardware implementation of fusion tree search algorithm. The proposed hardware can support all the discrete Gaussian distributions used in post-quantum digital signatures and key encapsulation algorithms (FALCON, qTESLA, and FrodoKEM), the homomorphic encryption library of SEAL, and other algorithms such BLISS digital signature and LP public-key encryption. Our proposed hardware can be configured at design-time to optimize a single configuration or at run-time to support multiple Gaussian distribution parameters. Our design, furthermore, has constant-time behavior by design, eliminating timing side-channel attacks—this is achieved by reading all table contents at the same time to also reduce the latency. The results on a Xilinx Virtex-7 FPGA show that our solution can outperform all prior proposals in area-delay product by 1.67–235.88×, only falling short to those designed for the LP encryption scheme. [ABSTRACT FROM AUTHOR]

This brief studies the privacy preserving average consensus (PPAC) of wireless sensor networks (WSNs). Note that most of the PPAC schemes only focus on the consensus of one-dimensional state, which is not suitable for the actual scenarios. In view of this, the multi-dimensional privacy-preserving average consensus (MPPAC) problem is considered in this brief, where the nodes are divided into two types, the sink nodes and the ordinary ones. A novel MPPAC algorithm is proposed by introducing the super-increasing sequence as well as the RSA algorithm, where the super-increasing sequence plays a key role in tackling the multi-dimensional measurement of the sensors, and the RSA algorithm realizes the privacy preserving average consensus among sink nodes. Simulation results illustrate the effectiveness of this proposed scheme. [ABSTRACT FROM AUTHOR]

A side-channel attack (SCA) hardened AES-128 and RSA crypto-processor in 14-nm CMOS with measured resistance to correlation power/electromagnetic analysis (CPA/CEMA) in both time and frequency domains is demonstrated. While previously reported linear low-dropout regulators (LDOs) offer improvements in minimum-time-to-disclose (MTD) of extracted key bytes in the time domain, their transformations are less effective against frequency-domain attacks. This article describes a non-linear digital LDO (NL-DLDO) with control loop randomizations that bolster SCA resistance in the frequency domain. The NL-DLDO cascaded with an AES engine augmented with arithmetic countermeasures enables > 250 K × improvement in MTD, with no CPA/CEMA/DNN attacks detected after 1-B encryptions, with 8% power and 10% area overheads incurred by arithmetic techniques. The RSA-4K crypto-processor implements exponent magnitude and timing randomizations along with dynamic memory addressing to mitigate time- and frequency-domain attacks. The countermeasures enable 711 × suppression in means separation in current/EM magnitudes from 3.1 mV to 4.35 μV, reducing attacker’s accuracy to an ineffective random guess classification, while limiting area and performance overheads to < 0.05% and 3.25%, respectively. [ABSTRACT FROM AUTHOR]

In intelligent transportation systems (ITS), communications between vehicles, i.e. vehicle-to-vehicle (V2V) communications are of greatest importance to facilitate autonomous driving. The current state-of-the-art for secure data exchange in V2V communications relies on public-key cryptography (PKC) consuming significant computational and energy resources for the encryption/decryption process and large bandwidth for the key distribution. To overcome these limitations, physical-layer security (PLS) has emerged as a lightweight solution by exploiting the physical characteristics of the V2V communication channel to generate symmetric cryptographic keys. Currently, key-generation algorithms are designed via empirical parameter settings, without resulting in optimum key-generation performance. In this paper, we devise a key-generation algorithm for PLS in V2V communications by introducing a novel channel response quantisation method that results in optimum performance via analytical parameter settings. Contrary to the current state-of-the-art, the channel responses incorporate all V2V channel attributes that contribute to temporal variability, such as three dimensional (3D) scattering and scatterers’ mobility. An extra functionality, namely, Perturbe-Observe (PO), is further incorporated that enables the algorithm to adapt to the inherent non-reciprocity of the V2V channel responses at the legitimate entities. Optimum performance is evidenced via maximisation of the key bit generation rate (BGR) and key entropy (H) and minimisation of the key bit mismatch rate (BMR). A new metric is further introduced, the so-called secret-bit generation rate (SBGR), as the ratio of the number of bits which are successfully used to compose keys to the total amount of channel samples. SBGR unifies BGR and BMR and is thus maximised by the proposed algorithmic process. [ABSTRACT FROM AUTHOR]

The rapid development of the Internet of Things (IoT) has led to the emergence of more and more novel applications in recent years. One of them is the e-health system, which can provide people with high-quality and convenient health care. Meanwhile, it is a key issue and challenge to protect the privacy and security of the user’s personal health record. Some cryptographic methods have been proposed such as encrypt user’s data before sharing it. However, it is complicated to share the data with multiple parties (doctors, health departments, etc.), due to the fact that data should be encrypted under each recipient’s keys. Although several $(t,n)$ threshold secret sharing schemes can share the data only need one encryption operation, there is a limitation that the decryption private key has to be reconstructed by one party. To offset this shortcoming, in this paper, we propose an efficient identity-based distributed decryption scheme for personal health record sharing system. It is convenient to share their data with multiple parties and does not require to reconstruct the decryption private key. We prove that our scheme is secure under chosen-ciphertext attack (CCA). Moreover, we implement our scheme by using the Java pairing-based cryptography (JPBC) library on a laptop and an Android phone. The experimental results show that our system is practical and effective in the electronic personal health record system. [ABSTRACT FROM AUTHOR]

In VANET, the privacy of the query becomes a serious concern for location-based services (LBS). An LBS scheme must, also, not breach the location privacy of the user vehicle. In order to protect query privacy of the vehicle user, the existing state-of-the-art schemes either reduce the accuracy of LBS or insert a trusted third party (TTP) between the vehicle user and the location server hosting the LBS scheme. Cryptographic constructs such as public-key encryption, Oblivious Transfer (OT), Private Information Retrieval (PIR), and homomorphic encryption are used to remove the TTP or increase the accuracy of the previous schemes. The problem with these existing schemes is that some of them are either inefficient or insecure. In order to address the security and privacy issues, we propose an efficient privacy-preserving mechanism for protecting the query privacy of the user, information content of the location server, and location privacy-preserving of the vehicle in the LBS scheme for VANET. In this scheme, the vehicle requests for services from the location server without revealing the query content to the location server. The location server sends all Point of Interests (POIs) to the vehicle, but the vehicle can only obtain the requested query content. The query privacy of the user and content privacy of the location server is preserved in the exchange. The proposed variant of the OT extension protocol is computationally and communicationally efficient and uses a lattice-based ring-Learning With Errors (ring-LWE) scheme as a Base-OT. [ABSTRACT FROM AUTHOR]

We introduce a new family of rank metric codes: Low Rank Parity Check codes (LRPC), for which we propose an efficient probabilistic decoding algorithm. This family of codes can be seen as the equivalent of classical LDPC codes for the rank metric. We then use these codes to design cryptosystems à la McEliece: more precisely we propose two schemes for key encapsulation mechanism (KEM) and public key encryption (PKE). Unlike rank metric codes used in previous encryption algorithms -notably Gabidulin codes - LRPC codes have a very weak algebraic structure. Our cryptosystems can be seen as an equivalent of the NTRU cryptosystem (and also to the more recent MDPC code-based cryptosystem) in a rank metric context, due to the similar form of the public keys. The present paper is an extended version of the article introducing LRPC codes, with important new contributions. We have improved the decoder thanks to a new approach which allows for decoding of errors of higher rank weight, namely up to $\frac {2}{3}(n-k)$ when the previous decoding algorithm only decodes up to $\frac {n-k}{2}$ errors. Our codes therefore outperform the classical Gabidulin code decoder which deals with weights up to $\frac {n-k}{2}$. This comes at the expense of probabilistic decoding, but the decoding error probability can be made arbitrarily small. The new approach can also be used to decrease the decoding error probability of previous schemes, which is especially useful for cryptography. Finally, we introduce ideal rank codes, which generalize double-circulant rank codes and allow us to avoid known structural attacks based on folding. To conclude, we propose different parameter sizes for our schemes and we obtain a public key of 3337 bits for key exchange and 5893 bits for public key encryption, both for 128 bits of security. [ABSTRACT FROM AUTHOR]

Reusable intellectual property (IP) cores from signal processing and multimedia form an integral part of consumer electronics (CE) systems. However, owing to the value it represents, it needs protection against important threats, such as piracy and illegal claim of ownership. This paper presents a novel multi-level encoding and encrypted-hash-based digital signature for protection of complex reusable IP core used in CE systems. For the first time in the literature, a digital signature-based IP core protection is proposed for digital signal processing (DSP) kernels. The proposed methodology is capable of encoding a DSP kernel application, followed by creating a digest of the encoded application to finally form a digital signature using RSA, which is subsequently implanted into the same design during architectural synthesis. The proposed approach on DSP benchmarks is capable of achieving higher robustness in terms of lower probability of coincidence - indicating stronger proof of authorship. The proposed approach achieves stronger robustness (on average by ~24.8%) as well as requires lesser storage hardware (on average reduction of ~14%) compared to similar prior work. [ABSTRACT FROM AUTHOR]

Freeman–Durden decomposition is a frequently used technique to analyze the scattering characteristics of multilook Polarimetric Synthetic Aperture Radar (POLSAR) data. When it is applied to the real POLSAR data, two problems emerge, namely, the volume scattering overestimation and negative powers. Many researchers think these two problems are caused by the insufficient decomposition algorithm, and several improvements are proposed. However, the improved decomposition algorithms become more and more complicated, and some new problems such as the decomposed component is not model based also emerge. In this paper, we try to solve the two problems through another way. We think they are caused not by the insufficient decomposition algorithm but by the dogmatic input. Freeman–Durden decomposition explicitly assumes reflection symmetry. Its input is a direct truncation of the measured coherency matrix. The truncation can be regarded as a reflection symmetry approximation (RSA) of the measured coherency matrix. We first show some reasons why we do not think the truncation is a good RSA. Then, a new RSA is proposed based on the sum of three reflection symmetry components derived from the measured coherency matrix. Experimental results with several real POLSAR images show that, if the new RSA is used as the input of Freeman–Durden decomposition, the above-mentioned two problems no longer exist. [ABSTRACT FROM AUTHOR]

Modular multiplication forms the basis of many cryptographic functions such as RSA, Diffie-Hellman key exchange, and ElGamal encryption. For large RSA moduli, combining the fast Fourier transform (FFT) with McLaughlin's Montgomery modular multiplication (MLM) has been validated to offer cost-effective implementation results. However, the conditional selections in McLaughlin's algorithm are considered to be inefficient and vulnerable to timing attacks, since extra long additions or subtractions may take place and the running time of MLM varies. In this work, we restrict the parameters of MLM by a set of new bounds and present a modified MLM algorithm involving no conditional selection. Compared to the original MLM algorithm, we inhibit extra operations caused by the conditional selections and accomplish constant running time for modular multiplications with different inputs. As a result, we improve both area-time efficiency and security against timing attacks. Based on the proposed algorithm, efficient FFT-based modular multiplication and exponentiation are derived. Exponentiation architectures with dual FFT-based multipliers are designed obtaining area-latency efficient solutions. The results show that our work offers a better efficiency compared to the state-of-the-art works from and above 2048-bit operand sizes. For single FFT-based modular multiplication, we have achieved constant running time and obtained area-latency efficiency improvements up to 24.3 percent for 1,024-bit and 35.5 percent for 4,096-bit operands, respectively. [ABSTRACT FROM AUTHOR]

Visible light communication systems are rapidly growing research areas with wide applications ranging from illumination and data communication. To achieve high data rates in such systems, a number of techniques have been employed such as equalization of transmission signals, deployment of complex data modulation and the use of multiple input multiple output (MIMO) systems. However, security in wireless telecommunication systems is a common concern. This paper proposes a secure MIMO-VLC systemthat relies on the position of the user by incorporating a new modified version of the Rivest-Shamir-Adleman (RSA) technique for encrypting the transmitted data in the media access control MAC layer. The performance of the positioning method is evaluated showing a positioning accuracy of less than 5 cm for a signal-to-noise ratio of 15 dB. Furthermore, the ability of the proposed system to control the size of the encrypted cell, depending on the application environment, is demonstrated. [ABSTRACT FROM AUTHOR]

In mobile communication, spatial queries pose a serious threat to user location privacy because the location of a query may reveal sensitive information about the mobile user. In this paper, we study approximate k nearest neighbor (kNN) queries where the mobile user queries the location-based service (LBS) provider about approximate k nearest points of interest (POIs) on the basis of his current location. We propose a basic solution and a generic solution for the mobile user to preserve his location and query privacy in approximate kNN queries. The proposed solutions are mainly built on the Paillier public-key cryptosystem and can provide both location and query privacy. To preserve query privacy, our basic solution allows the mobile user to retrieve one type of POIs, for example, approximate k nearest car parks, without revealing to the LBS provider what type of points is retrieved. Our generic solution can be applied to multiple discrete type attributes of private location-based queries. Compared with existing solutions for kNN queries with location privacy, our solution is more efficient. Experiments have shown that our solution is practical for kNN queries. [ABSTRACT FROM PUBLISHER]

Modular multiplication is the core operation in public-key cryptographic algorithms such as RSA and the Diffie-Hellman algorithm. The efficiency of the modular multiplier plays a crucial role in the performance of these cryptographic methods. In this paper, improvements to FFT-based Montgomery Modular Multiplication (FFTM $^3$ ) using carry-save arithmetic and pre-computation techniques are presented. Moreover, pseudo-Fermat number transform is used to enrich the supported operand sizes for the FFTM$^3$ . The asymptotic complexity of our method is $O(l\; \log\, l\; \log\; \log l)$ , which is the same as the Schönhage-Strassen multiplication algorithm (SSA). A systematic procedure to select suitable parameter set for the FFTM$^3$ is provided. Prototypes of the improved FFTM$^3$ multiplier with appropriate parameter sets are implemented on Xilinx Virtex-6 FPGA. Our method can perform 3,100-bit and 4,124-bit modular multiplications in 6.74 and 7.78 $\mu$ s, respectively. It offers better computation latency and area-latency product compared to the state-of-the-art methods for operand size of 3,072-bit and above. [ABSTRACT FROM AUTHOR]

Ring signature was first introduced in 2001. In a ring signature, instead of revealing the actual identity of the message signer, it specifies a set of possible signers. The verifier can be convinced that the signature was indeed generated by one of the ring members, however, she is unable to tell which member actually produced the signature. In this paper, we propose a generalized ring signature scheme and a generalized multi-signer ring signature based on the original ElGamal signature scheme. The proposed ring signature can achieve unconditional signer ambiguity and is secure against adaptive chosen-message attacks in the random oracle model. Comparing to ring signature based on RSA algorithm, the proposed generalized ring signature scheme has three advantages: (1) all ring members can share the same prime number and all operations can be performed in the same domain; (2) by combining with multi-signatures, we can develop the generalized multi-signer ring signature schemes to enforce cross-organizational involvement in message leaking. It may result in a higher level of confidence or broader coverage on the message source; and (3) the proposed ring signature is a convertible ring signature. It enables the actual message signer to prove to a verifier that only she is capable of generating the ring signature. [ABSTRACT FROM PUBLISHER]