International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 24 April 2015

Daniel R. L. Brown
ePrint Report ePrint Report
A remixed key is derived from a secret source key by applying a

public but unpredictable random function to the source key. A

remixed key models a key derived from a shared secret and a public

unpredictable salt, using a common, deterministic, pseudorandom

function---which is somewhat like TLS record-layer keys.

This report tries to validate the intuition that remixed keys are not

easy to surmise, in other words, that remixing does not introduce an

exploitable spike in the probability distribution of the remixed

key. The report provides pencil-and-paper proofs of numerical

bounds on the probability that an adversary can surmise a remixed

key, assuming a uniformly random source key and remix function. The

proofs are derived from a proof of an asymptotic result on

probability theory in a textbook by Shoup.

Expand

Additional news items may be found on the IACR news page.