Fast Correlation Attack Algorithm with List Decoding and an Application

An improved method for the fast correlation attack on certain stream ciphers is presented. The proposed algorithm employs the following decoding approaches: list decoding in which a candidate is assigned to the list based on the most reliable information sets, and minimum distance decoding based on Hamming distance. Performance and complexity of the proposed algorithm are considered. A desirable characteristic of the proposed algorithm is its theoretical analyzibility, so that its performance can also be estimated in cases where corresponding experiments are not feasible due to the current technological limitations. The algorithm is compared with relevant recently reported algorithms, and its advantages are pointed out. Finally, the proposed algorithm is considered in a security evaluation context of a proposal (NESSIE) for stream ciphers.