Timing Side Channel Attack on Key Derivation Functions

Abstract

A key derivation function is a function that generate one or more arbitrary length of cryptographic keys from a private string together with some public information. The generated cryptographic key(s) from this key derivation function proposals are generally indistinguishable from random binary strings of the same length based on formal mathematically proof. To date, there are designed of key derivation function proposals using cryptographic primitives such as hash functions, block ciphers and stream ciphers. However, there are limited security analysis of side channel attacks for the key derivation function proposals. This paper is to investigate the timing side channel attacks towards these three types of cryptographic primitives based key derivation function. Key derivation functions based on stream ciphers and block ciphers are input-dependent execution, the experiment results have shown that both key derivation functions proposals are vulnerable against timing side channel.