To guarantee security and privacy in image
transmission and archival applications adequate efficient bulk encryption techniques are
necessary which are able to cope with the vast amounts of image data involved. Experience
has shown that block-oriented symmetric product ciphers constitute an adequate design
paradigm for resolving this quest, since they can offer a very high level of security as
well as very high encryption rates.
In this contribution we introduce a new product cipher which encrypts large blocks of
plain-text (images) by repeated intertwined application of substitution and permutation
operations. While almost all of the current product ciphers use rather simple fixed
permutation operations on small data-blocks, our approach involves parameterizable (keyed)
permutations on large data-blocks (such as images) induced by specific chaotic systems
(Kolmogoroff-flows). By combining these highly unstable dynamics with an adaption of a
very fast shift register based PRNG we obtain a new class of secure product ciphers which
are firmly grounded on systems theoretic concepts offering many features that should make
them superior to comparable bulk encryption systems, especially when we are aiming at
efficient image data encryption.