Integral Based Fault Attack on LBlock

Abstract

LBlock is a 32-round lightweight block cipher presented at ACNS2011. In this paper, the fault attack on LBlock is explored. The first fault attack on LBlock was presented at COSADE2012, which can reveal the master key when faults are respectively induced at the end of the round from $24^{th}$ to $31^{st}$ round. When faults were injected at the end of the round from $25^{th}$ to $31^{st}$ round, the random bit fault model was adopted. While when the fault was induced into the right part of the end of $24^{th}$ round encryption, the attack only worked under the semi-random model, which means the adversary must know the induce position. In this paper, we firstly applied fault attack on LBlock successfully with faults induced into the right part at the end of $24^{th}$ round encryption under random nibble fault model. In our attack, eight 8-round integral distinguishers of LBlock are fully utilized to help determine the exact induce positions of faulty ciphertexts. Moreover, we also firstly apply fault attack with faults induced into the right part at the end of $23^{th}$ round encryption under semi-random nibble model. Finally, the computer simulation results verify the efficiency of our attack.