Non-Linearity and Security of Self Synchronizing Stream Ciphers
نویسندگان
چکیده
Several proposed chaos based ciphers exploit the ergodic property of chaotic orbits. As chaotic systems are unstable and have sensitive dependence on initial conditions, the main difficulty for the receiver is to reproduce the chaotic signal that has been generated by the sender in order to correctly decrypt the message. This is performed by a self synchronizing device. In discrete cryptography, the closest scheme is the so called self synchronizing stream cipher (SSSC). After recalling general security models for assessing cryptographic algorithms, we present SSSC scheme and two examples of cryptanalysis. In order to resist to theses attacks, the ciphering function must satisfy high non-linearity properties which are presented.
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