Differential Attacks on Reduced RIPEMD-160
In this work, we provide the first security analysis of reduced RIPEMD-160 regarding its collision resistance with practical complexity. The ISO/IEC standard RIPEMD-160 was proposed 15 years ago and may be used as a drop-in replacement for SHA-1 due to their same hash output length. Only few results have been published for RIPEMD-160 so far and most attacks have a complexity very close to the generic bound. In this paper, we present the first application of the attacks of Wang et al. on MD5 and SHA-1 to RIPEMD-160. Due to the dual-stream structure of RIPEMD-160 the application of these attacks is nontrivial and almost impossible without the use of automated tools. We present practical examples of semi-free-start near-collisions for the middle 48 steps (out of 80) and semi-free-start collisions for 36 steps of RIPEMD-160. Furthermore, our results show that the differential characteristics get very dense in RIPEMD-160 such that a full-round attack seems unlikely in the near future.
Keywordshash functions cryptanalysis semi-free-start collisions
Unable to display preview. Download preview PDF.
- 1.den Boer, B., Bosselaers, A.: Collisions for the Compression Function of MD-5. In: Helleseth, T. (ed.) EUROCRYPT 1993. LNCS, vol. 765, pp. 293–304. Springer, Heidelberg (1994)Google Scholar
- 2.Damgård, I.B.: A Design Principle for Hash Functions. In: Brassard, G. (ed.) CRYPTO 1989. LNCS, vol. 435, pp. 416–427. Springer, Heidelberg (1990)Google Scholar
- 6.International Organization for Standardization: ISO/IEC 10118-3:2004. Information technology – Security techniques – Hash-functions – Part 3: Dedicated hash-functions (2004), http://www.iso.org/
- 7.Mendel, F., Nad, T., Schläffer, M.: Finding SHA-2 Characteristics: Searching through a Minefield of Contradictions. In: Lee, D.H., Wang, X. (eds.) ASIACRYPT 2011. LNCS, vol. 7073, pp. 288–307. Springer, Heidelberg (2011)Google Scholar
- 8.Mendel, F., Nad, T., Schläffer, M.: Collision Attacks on the Reduced Dual-Stream Hash Function RIPEMD-128. In: Canteaut, A. (ed.) FSE 2012. LNCS, vol. 7549, pp. 226–243. Springer, Heidelberg (2012)Google Scholar
- 10.Merkle, R.C.: One Way Hash Functions and DES. In: Brassard, G. (ed.) CRYPTO 1989. LNCS, vol. 435, pp. 428–446. Springer, Heidelberg (1990)Google Scholar
- 11.National Institute of Standards and Technology: Announcing Request for Candidate Algorithm Nominations for a New Cryptographic Hash Algorithm (SHA-3) Family. Federal Register 27(212), 62212–62220 (November 2007), http://csrc.nist.gov/groups/ST/hash/documents/FR_Notice_Nov07.pdf
- 14.Sasaki, Y., Wang, L.: 2-Dimension Sums: Distinguishers Beyond Three Rounds of RIPEMD-128 and RIPEMD-160. Cryptology ePrint Archive, Report 2012/049 (2012), http://eprint.iacr.org/
- 17.Wang, X., Yin, Y.L., Yu, H.: Finding Collisions in the Full SHA-1. In: Shoup, V. (ed.) CRYPTO 2005. LNCS, vol. 3621, pp. 17–36. Springer, Heidelberg (2005)Google Scholar