The Conditional Correlation Attack: A Practical Attack on Bluetooth Encryption

Motivated by the security of the nonlinear filter generator, the concept of correlation was previously extended to the conditional correlation, that studied the linear correlation of the inputs conditioned on a given (short) output pattern of some specific nonlinear function. Based on the conditional correlations, conditional correlation attacks were shown to be successful and efficient against the nonlinear filter generator. In this paper, we further generalize the concept of conditional correlations by assigning it with a different meaning, i.e. the correlation of the output of an arbitrary function conditioned on the unknown (partial) input which is uniformly distributed. Based on this generalized conditional correlation, a general statistical model is studied for dedicated key-recovery distinguishers. It is shown that the generalized conditional correlation is no smaller than the unconditional correlation. Consequently, our distinguisher improves on the traditional one (in the ...

• Type: Conference
• Year: 2005
• Where: CRYPTO
• Authors: Yi Lu 0002, Willi Meier, Serge Vaudenay
• Keywords: Conditional Correlation Attack, Conditional Correlations, CRYPTO 2005, Generalized Conditional Correlation