Leakage Quantification of Cryptographic Operations

Perfectly secure protocols are often too inefficient performance wise to be used in a practical setting. On the other hand, an insecure (but faster) protocol might be deemed secure for a particular setting. Recent research has thus focused on precise leakage quantification of a security protocol. In this context, we first give precise leakage quantification of a basic cryptographic primitive, that of multiplicative hiding. We then show how the approach can be extended to compute worst case leakage bounds of arbitrary compositions of cryptographic operations. The composition results make our bounds applicable to a wide range of general security protocols.