Research on Fault-Electromagnetic Attack on Block Cipher

It is one of the important factors in iterative block ciphers design that proper rounds are used to resist differential analysis, linear analysis and many other kinds of attack. Block ciphers usually adopt loop codes in software and repetition structures in hardware in order to reduce complexity and cost. This paper presents an effective fault-electromagnetic attack which can change the rounds of block ciphers in running process, by inducing appropriate fault to the cryptographic chip. The executing rounds of the attacked block cipher can be detected from the electromagnetic radiation track of cryptographic chip. Then the secret key can be deduced directly or with simple mathematical analysis. The simulation result of lightweight block cipher PRESENT shows that the suggested attack is feasible and efficient, when it is implemented with single chip microcomputer. Furthermore, countermeasures are given to resist this kind of attack.