Fault-based Cryptanalysis On Several Block Ciphers

Side channel analysis is different from traditional cryptanalysis. It considers the process of encryption as a kind of physical process, and exploits physical characters from the implementation of cryptosystems to discover the secret parameters. Fault-based cryptanalysis is one of the side channel analysis. This paper studies the fault-based cryptanalysis on several block ciphers.A bit-fault-based differential fault analysis and a permanent-fault-based attack on DES in [11] are elaborated. By further research, some notes on the differential fault analysis are given. Taking example for DES, the relationship of differential analysis and differential fault analysis is studied.A bit-fault-based differential fault analysis on AES in [6] is described. Two attack algorithms are brought forward and simulated. The successful probability of two algorithms is analyzed. The attack must be successful, provided the number of fault induction is enough. A countermeasure to this attack is advanced. An improved attack method is put forward. The improved one has advantages over the original one.A bit-fault-based differential fault analysis on IDEA is brought forward for the first time. The ability to induct random transient bit faults into special location with special time is required. If the bit fault is uniform random, the attack will accomplish with the probability of more than 1/2, after 520 fault inductions. The best case when the attack accomplishes is to disclose the initial key by verifying 2 20 possible keys.A permanent-fault-based attack on IDEA is also given for the first time. Cryptography device will loss the function of normal encryption, when permanent faults are inducted, but such attack is more effective.