Methods of differential fault attack on LBlock with analysis of probability

A new method of differential fault attack was proposed, which is based on the nibble-group differential diffusion property of the lightweight block cipher LBlock. Theoretical proof and experimental results both show that six fault injections in last three rounds are needed to recover the main key. On the basis of the statistical regularity of the S-box differential distribution, the probability of recovering round key was calculated. Then the expectation of number of fault injections when recovering main key K can be estimated, which is 8.35. Finally, experimental data verifies the correctness of the theoretical model.