FAST ENCRYPTION OF IMAGE DATA USING CHAOTIC KOLMOGOROV FLOWS

To guarantee security and privacy in image and video archival applicat ions, efficient bulk encryption techniques are necessary which are eas ily implementable in soft- and hardware and are able to cope with the vast amounts of data involved. Experience has shown that block-oriente d symmetric product ciphers constitute an adequate design paradigm for resolving this task, since they can offer a very high level of securi ty as well as very high encryption rates, in this contribution we intr oduce a new product cipher which encrypts large blocks of plaintext by repeated intertwined application of substitution and permutation oper ations. While almost all of the current product ciphers use fixed (pre defined) permutation operations on small data blocks, our approach inv olves parametrizable (keyed) permutations on large data blocks (whole images) induced by specific chaotic systems (Kolmogorov flows). By com bining these highly unstable dynamics with an adaption of a very fast shift register based pseudo-random number generator, we obtain a new c lass of computationally secure product ciphers which offer many featur es that make them superior to contemporary bulk encryption systems whe n aiming at efficient image and video data encryption. (C) 1998 SPIE a nd IS&T. [S1017-9909(98)00402-4].