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Stream cipher based key derivation function

A key derivation function (KDF) is used to generate one or more cryptographic keys from a private string together with some public information. To date, most of the existing KDF proposals are designed using hash functions and block ciphers. This paper proposes alternative designs for constructing KDFs using stream ciphers. We show that these designs are secure in relation to the adaptive chosen context information model with single salt (CCS) security model from Krawczyk based on the assumption that the underlying stream ciphers are secure. We simulate instances of these stream cipher based KDFs using three eStream finalists: Trivium, Sosemanuk and Rabbit. The simulation results indicate that the stream cipher based KDFs offer significant efficiency advantages (in terms of running time) over hash function and block cipher based KDFs.