Sedat Akleylek

An Efficient Lattice-Based Signature Scheme with Provably Secure Instantiation

In view of the expected progress in cryptanalysis it is important to find alternatives for currently used signature schemes such as RSA and ECDSA. The most promising lattice-based signature schemes to replace these schemes are CRYPTO 2013 and GLP CHES 2012. Both come with a security reduction from a lattice problem and have high performance. However, their parameters are not chosen according to their provided security reduction, i.e., the instantiation is not provably secure. In this paper, we present the first lattice-based signature scheme with good performance when provably secure instantiated. To this end, we provide a tight security reduction for the new scheme from the ring learning with errors problem which allows for provably secure and efficient instantiations. We present experimental results obtained from a software implementation of our scheme. They show that our scheme, when provably secure instantiated, performs comparably with BLISS and the GLP scheme.

On the Construction of and Binary Matrices with Good Implementation Properties for Lightweight Block Ciphers and Hash Functions

We present an algebraic construction based on state transform matrix (companion matrix) for (where , being a positive integer) binary matrices with high branch number and low number of fixed points. We also provide examples for and binary matrices having advantages on implementation issues in lightweight block ciphers and hash functions. The powers of the companion matrix for an irreducible polynomial over with degree 5 and 4 are used in finite field Hadamard or circulant manner to construct and binary matrices, respectively. Moreover, the binary matrices are constructed to have good software and hardware implementation properties. To the best of our knowledge, this is the first study for (where , being a positive integer) binary matrices with high branch number and low number of fixed points.

Efficient arithmetic for lattice-based cryptography on GPU using the CUDA platform

The demand to lattice-based cryptographic schemes has been inreasing. Due to processing unit having multiple processors, there is a need to implements such protocols on these platforms. Graphical processing units (GPU) have attracted so much attention. In this paper, polynomial multiplication algorithms, having a very important role in lattice-based cryptographic schemes, are implemented on a GPU (NVIDIA Quadro 600) using the CUDA platform. FFT-based and schoolbook multiplication methods are implemented in serial and parallel way and a timing comparison for these techniques is given. Its concluded that for the polynomials whose degrees are up to 2000 the fastest polynomial multiplication method is iterative NTT.

On the Polynomial Multiplication in Chebyshev Form

We give an efficient multiplication method for polynomials in Chebyshev form. This multiplication method is different from the previous ones. Theoretically, we show that the number of multiplications is at least as good as Karatsuba-based algorithm. Moreover, using the proposed method, we improve the number of additions slightly. We remark that our method works efficiently for any N and it is easy to implement. To the best of our knowledge, the proposed method has the best multiplication and addition complexity for the N-term polynomial multiplication in Chebyshev form with 3 ≤ N ≤ 13.

On the generalisation of special moduli for faster interleaved montgomery modular multiplication

In this study, the authors give a generalisation of special moduli for faster interleaved Montgomery modular multiplication algorithm with simplified pre-computational phase for GF(pn ), where p ≥ 2 is a prime number and n is a positive integer. The authors propose different sets of moduli that can be used in elliptic curve crytographic applications and pairing-based cryptography. Moreover, this method also leads to efficient implementations for the elliptic curve parameters given in standards. It is shown that one can obtain efficient Montgomery modular multiplication architecture in view of the number of AND gates and XOR gates by choosing proposed sets of moduli. The authors eliminate final substraction step with proposed sets of moduli. These methods are easy to implement for hardware.

Modified Redundant Representation for Designing Arithmetic Circuits with Small Complexity

We give a modified redundant representation for designing arithmetic circuits with small complexity. Using our modified redundant representation, we improve many of the complexity values significantly. Our method works for any finite field. We also give some applications in cryptography.

Generalisation of Hadamard matrix to generate involutory MDS matrices for lightweight cryptography.

In this study, the authors generalise Hadamard matrix over Fn 2(m)n and propose a new form of Hadamard matrix, which they call generalised Hadamard (GHadamard) matrix. Then, they focus on generating lightweight (involutory) maximum distance separable (MDS) matrices. They also extend this idea to any k × k matrix form, where k is not necessarily a power of 2. The new matrix form, GHadamard matrix, is used to generate new 4 × 4 involutory MDS matrices over Fn 2(4)n and Fn 2(8)n, and 8 × 8 involutory/non-involutory MDS matrices over Fn 2(4)n by considering the minimum exclusive OR (XOR) count, which is a metric defined to estimate the hardware implementation cost. In this context, they improve the best-known results of XOR counts for 8 × 8 involutory/non-involutory MDS matrices over Fn 2(4)n.

E-Kitap Ödünç Alma Yönetim Sistemi İçin Yeni Model

In todays information-age world, most libraries use traditional borrowing methods. These conventional methods have some disadvantages such as torn and loss of books, and no access to books at that moment. In this paper, to overcome such disadvantages, we propose a novel e-book borrowing mechanism considering digital rights management. By combining the techniques given in this paper, e-books are protected against copying, distributing, printing and unauthorized use while borrowing and using. An infrastructure is designed for users to access books through electronic devices. In this structure, e-books are user-specific encrypted. Even if the e-book files are copied by unauthorized users, the key cannot be accessed by the copied device since the target platform doesn’t have this key. Thus, the borrowed book is prevented from being used by an unauthorized user. Then, the borrowed books can be checked via cloud system technologies by sharing resources between devices. Moreover, even if the books are copied and distributed, the malicious user can be found via watermarking. The main difference to the previous studies is that QR code authentication, which is generated by public key cryptographic techniques, enables the use of books on different devices.

An Artificial Bee Colony Algorithm for Solving the Weapon Target Assignment Problem

In this paper, we deal with the static weapon target assignment (WTA) problem which is a hard combinatorial optimization problem having some industrial applications. The aim of the WTA problem is to find an assignment of weapons to targets with the minimum total survival value of the targets. The WTA problem is known to be NP-complete problem. In this paper, we propose a novel artificial bee algorithm to give an efficient solution to the WTA problem. We test the proposed algorithm with benchmark problem instances and compare it with some other meta-heuristics in the literature. Computational tests show that our algorithm is competitive.

A Modified Parallel Learning Vector Quantization Algorithm for Real-Time Hardware Applications

In this study a modified learning vector quantization (LVQ) algorithm is proposed. For this purpose, relevance LVQ (RLVQ) algorithm is efficiently combined with a reinforcement mechanism. In this mechanism, it is shown that the proposed algorithm is not affected constantly by both relevance–irrelevance input dimensions and the winning of the same neuron. Hardware design of the proposed scheme is also given to illustrate the performance of the algorithm. The proposed algorithm is compared to the corresponding ones with regard to success rate and running time.