Non‐singular sequence folding‐based pseudorandom key generation algorithm for cryptographic processor

Abstract

In this paper, a new algorithm to construct the non-linear-based Boolean function using non-singular sequence folding technique is proposed to generate pseudorandom binary key sequence for cryptographic processor. Unlike the conventional methodology to generate recursive pseudorandom nibble of 15 (60-bit) from minimum seed of four bits, the proposed algorithm has the novelty to generate non-recursive pseudorandom nibble of 63 (252-bit) from the same minimum seed of four bits. In this proposed algorithm, a given binary sequence is converted to de Bruijn sequence and folded to minimum state with the strategy of binary encoding, which supports to determine the non-linear Boolean function. Further, the next state functions with minimum logic complexity is formulated using the algebraic normal form to generate nonrecursive pseudorandom binary sequence. The key stream analysis is performed, and randomness tests for the generated pseudorandom binary sequence (key stream) is validated using National Institute of Standards and Technology test suite. The proposed algorithm in this paper has improved in terms of sequence size and number of stages compared with existing algorithms. secured system, in which the basic techniques are pooled together. Blaze [8] postulates that the asymmetric cryptography is more secure than the symmetric in key distribution and exchange, and the key size should be larger than the symmetric cryptographic key. Thus, the pseudorandom key size, which is static or dynamic, plays the vital and most critical part in cryptographic processor apart from the cryptographic algorithm.This paper conferred the construction of a non-linearbased Boolean function using non-singular sequence folding technique to generate non-recursive pseudorandom binary key sequence for cryptographic processor. In order to determine the non-linear Boolean functions, a given binary sequence is converted to de Bruijn sequence and folded to minimum state with the strategy of binary encoding using proposed algorithm 1. Further, the constructed de Bruijn sequence fold is used to construct the non-linear Boolean functions with the minimum number of stages using proposed algorithm 2. Further, the next state functions with minimum logic complexity is constructed using the algebraic normal form (ANF) to generate non-recursive pseudorandom binary sequence (key stream) using proposed algorithm 3. Thus, the generated non-recursive pseudorandom binary key sequence satisfies the randomness properties and unpredictable, so that the adversary could not disrupt the key. The proposed algorithm for generating the non-recursive pseudorandom key sequence can be used for any application that requires randomizing the data for security. Such cryptographic applications include wireless communications, data transmission, and many others [9][10][11][12]. The rest of the paper is structured with the preliminary concept, algorithmic development, analysis, and testing. Section 2 highlights the concepts of de Bruijn sequence and the necessity of feedback Boole...