Improved Cryptanalysis of Polar Bear

• In this paper we propose a Guess-and-Determine based initial state recovery attack on Polar Bear, one of the ECRYPT stream cipher project candi-dates. The computational complexity and success probability of our attack are O(231) and 2-26.4 respectively. Our attack can be considered as one with compu-tational complexity of O(257.4) which is much better than the attack recently proposed by J. Mattsson with computational complexity of O(279).

Ämnesord

NATURVETENSKAP  -- Data- och informationsvetenskap -- Datavetenskap (hsv//swe)

NATURAL SCIENCES  -- Computer and Information Sciences -- Computer Sciences (hsv//eng)

Nyckelord

Stream Cipher

Guess-and-Determine Attack

Polar Bear

ECRYPT

Security Evaluation.

Publikations- och innehållstyp

ref (ämneskategori)

kon (ämneskategori)