Forgery and Partial Key-Recovery Attacks on HMAC and NMAC Using Hash Collisions
- Cite this paper as:
- Contini S., Yin Y.L. (2006) Forgery and Partial Key-Recovery Attacks on HMAC and NMAC Using Hash Collisions. In: Lai X., Chen K. (eds) Advances in Cryptology – ASIACRYPT 2006. ASIACRYPT 2006. Lecture Notes in Computer Science, vol 4284. Springer, Berlin, Heidelberg
In this paper, we analyze the security of HMAC and NMAC, both of which are hash-based message authentication codes. We present distinguishing, forgery, and partial key recovery attacks on HMAC and NMAC using collisions of MD4, MD5, SHA-0, and reduced SHA-1. Our results demonstrate that the strength of a cryptographic scheme can be greatly weakened by the insecurity of the underlying hash function.