To guarantee security and privacy in image
and video archival applications, efficient bulk encryption techniques are necessary which
are easily implementable in soft- and hardware and are able to cope with the vast amounts
of data involved. Experience has shown that block-oriented symmetric product ciphers
constitute an adequate design paradigm for resolving this task, 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 by repeated intertwined application of substitution and permutation operations.
While almost all of the current product ciphers use fixed (predefined) permutation
operations on small data blocks, our approach involves parameterizable (keyed)
permutations on large data blocks (whole images) induced by specific chaotic systems
(Kolmogorov flows). By combining these highly unstable dynamics with an adaption of a very
fast shift register based pseudo-random number generator we obtain a new class of
computationally secure product ciphers which offer many features that make them superior
to contemporary bulk encryption systems when aiming at efficient image and video data
encryption.