Security Group Seminar, 9th December 1994
- Speaker:
- Luke O'Connor, Security Group, Cooperative Research Centre for
Distributed Computing, Brisbane, Australia
- Date:
- Friday 9th December at 4.15pm
- Place:
- Room TP4, Computer Laboratory
- Title:
- A MARKOV APPROACH TO THE DESIGN OF PRODUCT CIPHERS
Most modern symmetric key ciphers are instances of product ciphers,
which were first suggested by Shannon soon after WWII. Such ciphers,
which include DES, FEAL, LOKI and IDEA, iterate a fixed round function
F to produce the encryption function. This iterative structure suggests
that they can be modelled as a Markov chain, whose powers correspond in
some manner to the iteration of F.
In this talk we will show that two highly acclaimed attacks,
differential and linear cryptanalysis, can be modelled as Markov chains
and that most product ciphers will be resistant to these attacks given
a sufficient number of rounds.
Security Group Seminar, 9th December 1994 / Mark.Lomas@cl.cam.ac.uk