Public Key Encryption Secure Against Related Randomness Attacks

摘要

Most cryptographic primitives are designed under the assumption that perfect (uniform) randomness is available. Unfortunately, however, random number generators (RNGs) are notoriously hard to implement and test, and we have seen many examples of the failures of RNGs in practice. Motivated by the challenge of designing public key encryption secure under randomness failure, Paterson, Schuldt, and Sibborn (PKC 2014) introduced a security notion called related randomness attack (RRA) security. This notion captures security against adversaries that are allowed to control the randomness used in the encryption scheme, but still requires that messages encrypted under an honestly generated public key remain hidden, given that certain restrictions are placed on the adversaries' queries. RRA security is one of the promising security notions that allows us to hedge against randomness failures in the usage of public key encryption. In this talk, I will give a brief survey of the topic, in particular the formalizations, existing results, and techniques used for achieving RRA security.