Fault Analysis Against Final Round of L-Block

Abstract

A lightweight block cipher L-Block was presented in ACNS 2011 with various security analysis for hardware-constrained environment. Parameter such as clock cycle, throughput and gate equivalent (GE) were investigated to prove the cipher strength. This paper provides the ineffective fault analysis (IFA) and differential fault analysis (DFA) on L-Block. A byte-wise random fault injection and stuck-at-0/1 models efficiently retrieved the unknown key in Feistel function. Byte-wise fault model requires four faulty ciphertexts which reduce key search space from 2 32 to 2 8. Ineffective stuck-at-fault model extracted round key in 32 attempts on software-simulated platforms. We simulated both attacks on INTEL(R) CORE(TM) i7-8700 CPU @ 3.20 GHz and 3.19 GHz computer system.