Abstract
In the era of rapid digital technology development, the volume of information transmitted incyberspace is significantly increasing, thereby intensifying the need to ensure confidentiality and the protectionof personal data. Modern cryptographic methods are used for such purposes. One of the most widely usedencryption algorithms is Advanced Encryption Standard (AES), which employs substitution box (S-box) toenhance the security of the encryption process. S-box is one of the important components of the block algorithm.The robustness of an S-box is largely determined by its architecture and algebraic basis. In this paper, a methodfor constructing S-boxes is proposed based on various alternative irreducible polynomials with the addition of aconstant 8-bit vector, different from that used in the AES standard. A total of 16 S-boxes were constructed andtheir performance was evaluated using standard cryptographic criteria, including nonlinearity, strict avalancheeffect, etc. The results demonstrated that the proposed S-boxes exhibit performance comparable to that of thestandard AES S-box. This study is conducted within the framework of grant funding from the Science Committeeof the Ministry of Education and Science of the Republic of Kazakhstan (grant No. AP19677422).