CASC 3N vs. 4N: Effect of Increasing Cellular Automata Neighborhood Size on Cryptographic Strength

Stream ciphers are symmetric cryptosystems that rely on pseudorandom number generators (PRNGs) as a primary building block to generate a keystream. Stream ciphers have been extensively studied and many designs were proposed throughout the years. One of the popular designs used is the combination of linear feedback shift registers (LFSRs) and nonlinear feedback shift registers (NFSRs). Although this design is suitable for both software and hardware implementation and provides a good randomness behavior, it is still subject to attacks such as fault attacks and correlations attacks. Cellular automata (CAs) based stream ciphers are another design class that has been proposed. CAs display good cryptographic properties as well as a good randomness behavior, also high computational speed and a higher level of security. The use of CAs as cryptographic primitives is not recent and has been thoroughly investigated, especially the use of three-neighborhood one-dimensional cellular automata. In this article, the authors investigate the impact of increasing the neighborhood size of CAs on the security level and the cryptographic properties provided. Thereafter, four-neighborhood one-dimensional CAs are studied and a stream cipher algorithm is proposed. The security of the proposed algorithm is demonstrated by using the results of standard tests (i.e. NIST Test Suite and Dieharder Battery of Tests), particularly by computing the cryptographic properties of the used CAs and by showing the resistance of the suggested algorithm to mostly known attacks.

@article{Ziani2020,
  title     = {CASC 3N vs. 4N: Effect of Increasing Cellular Automata Neighborhood Size on Cryptographic Strength},
  journal   = {International Journal of Advanced Computer Science and Applications},
  volume    = {11},
  number    = {4},
  year      = {2020},
  publisher = {The Science and Information Organization},
  author    = {Fatima Ezzahra Ziani and Anas Sadak and Charifa Hanin and Bouchra Echandouri and Fouzia Omary},
  doi       = {10.14569/IJACSA.2020.0110442},
  url       = {https://doi.org/10.14569/IJACSA.2020.0110442}
}