Related-Key Differential Attacks on Reduced-Round LBlock

LBlock, as one of the typical lightweight encryption schemes, is a 32-round block cipher with 64 bit and 80 master key. It can be widely applied in IoT environment because its friendly software hardware implementations. Since it came out, has encountered many attacks. In this paper, we evaluate LBlock’s ability against related-key differential attack more accurately based on SMT method. On hand, propose tighter lower bounds minimal number active S-boxes for up to 19 rounds which are 8 than previous ones. Then, upper total probabilities LBlock first time. other suitable 17-round distinguisher, attacks 22- 23-round LBlock. Each these time complexity data ones same