Instant Ciphertext-Only Cryptanalysis of GSM Encrypted Communication (2003)

This paper is the first to propose the ciphertext only/short known plaintext attack on A5/1 applicable to real world GSM.

 Cryptanalytic Time/Memory/Data tradeoffs for Stream Ciphers (2000)

This paper describes a method to use multiple overlapping data samples D of the keystream to reduce the size of the keyspace to be covered by lookup tables by a factor of D.