Search

Security efficiency and hardware efficiency are equally important when designing a block cipher. In this paper, we propose a new block cipher that uses string transformations and requires less memory and fewer computational resources, making it suitable for highly constrained environments. We compare the performance of our design with AES-128 and quasigroup-based block cipher INRU in the cipher block chaining (CBC) mode of operation using the National Institute of Standards and Technology (NIST) test suite. We then analyze our design against the standard linear, differential, and algebraic attacks. Choosing suitable S-boxes and a quasigroup of a smaller order does not compromise the security of the cipher, but the storage space is reduced compared with AES-128 and INRU. [ABSTRACT FROM AUTHOR]

In this paper, we present a new test for stream ciphers named the 'Bit Inclusion Test (BIT)'. This test provides an enhancement to the conventional avalanche test for stream ciphers. This test is efficient and includes the conventional avalanche test. Additionally, it can capture the shortcomings which escape the conventional avalanche test. We also demonstrate, with examples, how BIT is capable of going deeper into the structure of crypto-algorithms and detecting internal biases which make an algorithm susceptible to cryptanalytic attacks. [ABSTRACT FROM AUTHOR]

'Rotation and shift' based diffusion functions are used in modern ciphers especially in ARX (Addition, Rotation, and XOR) based designs. They are preferred over other alternatives as they are efficient and lightweight. Usually, such diffusion functions map an n-bit block to another n-bit block. One of the requirements for an n-bit to n-bit diffusion function is that, it should be invertible. In this paper, we present mathematical models for different classes of 'rotation and shift' based diffusion functions and explore their invertibility. We derive sufficient conditions under which diffusion functions of these classes are invertible. [ABSTRACT FROM AUTHOR]

The security of block ciphers solely depends on the S-boxes used in their design. Hence, for a secure block cipher, S-boxes should be chosen very thoughtfully. n-ary quasigroups of different orders and for different values of n are being used to design various cryptographic primitives. In the literature, many algorithms based on the quasigroups have been proposed for the generation of S-boxes of order 4. However, in this article, we propose a general method for the construction of symmetric S-boxes of even order using ternary quasigroups of order 4 with certain properties. These S-boxes give strong resistance against linear, differential, algebraic, and DPA attacks and hence provide good cryptographic properties. [ABSTRACT FROM AUTHOR]

The period of a binary sequence generated by feedback with carry shift register (FCSR) depends on the connection integer (q) of the register. We define FCSR primes as primes generating maximum possible period sequences when used as connection integer of an FCSR. Hence, to design good FCSR pseudorandom generators, one needs suitable feedback primes. The authors of this article study some properties about these primes and give algorithms to generate some of them. The first algorithm is somewhat straightforward and is based on the criterion given in Arnault and Berger. We propose two new algorithms for the efficient generation of FCSR primes. Comparison between these algorithms, supported by experimental and analytical results is presented. Further, we address the question of quantification of such primes and derive some explicit bounds. [ABSTRACT FROM AUTHOR]

Cryptographic properties of permutations viz non-linearity, affine equivalence, and mode transform have been studied in the literature, treating them as bijections on ℤn. In this article, the authors consider them as bijection on an arbitrary finite commutative ring with unity. Treating them this way, they achieve a generalization of the above mentioned properties. The authors also propose an algorithm for computing non-linearity in their generalized scenario, which is faster compared to the direct approach in many cases. [ABSTRACT FROM PUBLISHER]