Block Cipher Generation Model: A Step Towards Generative Ciphers

The protection of confidential information is a worldwide challenge, and block ciphers are the most reliable option by which data security is accomplished. To the best of our knowledge, this type of research is being performed for the first time, unlocking new avenues for block cipher design research, shifting the paradigm from cryptographer-designed ciphers to computationally generated. We propose a computational model named Block Cipher Design Generation Model (BCDGM) to generate a complete design of novel block ciphers and their primitives, such as cipher structures, S-boxes, inverse S-boxes, P-boxes, round functions, half-round functions, and derived keys, in an automated manner without the participation of cryptographers. To accomplish this goal, BCDGM only requires high-quality quantum random bits as input to generate a myriad of new block ciphers. A quantum circuit is designed over the International Business Machines Corporation (IBM) Quantum Santiago computer to generate high-quality random bits. BCDGM itself and all its generated cipher structures and primitives are invariably transparent, unreproducible, and nondeterministic due to their sole reliance on quantum random bits. Furthermore, every decision made by BCDGM is randomized. As a result, potential vulnerabilities and attacks that exist in other ciphers are bypassed in BCDGM-generated ciphers. Extensive experimentation was conducted, generating more than fifty thousand new block cipher designs tested over 107 terabytes of data. Generated ciphers are compared with twelve reputable standard block ciphers, including five AES competition finalists. The results show that the proposed block ciphers occasionally surpass standard ciphers and achieve equivalent security strength in many cases. The implementation of the proposed model is publicly available.