Practical Electromagnetic Template Attack on HMAC

Pierre-Alain Fouque (1, 2, 3) , Gaëtan Leurent (3) , Denis Réal (4) , Frédéric Valette (4)

1 LIENS - Laboratoire d'informatique de l'école normale supérieure
2 CASCADE - Construction and Analysis of Systems for Confidentiality and Authenticity of Data and Entities
3 ENS-PSL - École normale supérieure - Paris
4 DGA.MI - DGA Maîtrise de l'information

In this paper, we show that HMAC can be attacked using a very efficient side channel attack which reveals the Hamming distance of some registers. After a profiling phase which requires access to a similar device that can be configured by the adversary, the attack recovers the secret key on one recorded execution of HMAC-SHA-1 for example, on an embedded device. We perform experimentations using a NIOS processor executed on a Field Programmable Gate Array (FPGA) to confirm the leakage model. Besides the high efficiency of this attack, $2^32\cdot 3^k$ where $k$ is the number of 32-bit words of the key, that we tested with experimentations, our results also shed some light on the on the requirements in term of side channel attack for the future SHA-3 function. Finally, we show that our attack can also be used to break the confidentiality of network protocols usually implemented on embedded devices. We have performed experiments using a NIOS processor executed on a Field Programmable Gate Array (FPGA) to confirm the leakage model. We hope that our results shed some light on the requirements in term of side channel attack for the future SHA-3 function.

Domaines: Cryptographie et sécurité [cs.CR]

Pierre-Alain Fouque, Gaëtan Leurent, Denis Réal, Frédéric Valette. Practical Electromagnetic Template Attack on HMAC. Cryptographic Hardware and Embedded Systems - CHES 2009, 11th International Workshop, 2009, Lausanne, Switzerland. pp.66-80, ⟨10.1007/978-3-642-04138-9_6⟩. ⟨inria-00556681⟩