Improved Data Complexity of Attacks on RC5

Alex Biryukov, Vesselin Velichkov

Research output: Contribution to conferencePaperpeer-review


In this paper we improve the average data complexity of the best attacks on RC5 by about a factor of 4. The main contribution is an improved filtration procedure for detecting good pairs from noise. It is an extended variant of the filtration algorithm proposed by Biryukov et al. and applied in the best attack on the cipher to date. With the new technique we reduce the data complexity of the attacks on RC5 reduced to 8 and 10 rounds by a factor of 22.7 and 21.35 respectively and we provide an estimation for the full cipher. This is the first new result on RC5 for the past 16 years since the publication of Biryukov et al.’s attacks
Original languageEnglish
Number of pages8
Publication statusPublished - 2015
EventEarly Symetric Crypto - Clervaux, Luxembourg
Duration: 12 Jan 201516 Jan 2015


ConferenceEarly Symetric Crypto
Abbreviated titleESC-2015

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