Summary
International Symposium on Nonlinear Theory and its Applications
2010
Session Number:B2L-C
Session:
Number:B2L-C5
CA-based Stream Cryptography with Variable-Length Key
Masaki Igarashi, Masayuki Ikebe, Junichi Motohisa,
pp.334-337
Publication Date:2010/9/5
Online ISSN:2188-5079
Summary:
Cellular automata (CA) stream cryptography with a variable-length key was developed. CA are used to design secret key cryptography systems based on a onetime pad cipher. To change the connection of cells of onedimensional CA which generate pseudo-random number sequences (PNS), the state of the cells can be shifted and the key length of the cryptography can also be controlled. Arranging combinations and mixing CA-chaos sequences in time and space conceals a feature of the CA-chaos sequences, and their frequency characteristics are similar to those of white noise. Moreover, pseudo-random-numbers are extracted with consideration of spatial direction and the random numbers are selected by the internal state of the cipher system for internal-state-recovery attacks. The cipher system was simulated, and the encryption/decryption throughput was 64 bit/cycle.