Barriers in Cryptography with Weak, Correlated and Leaky Sources
There has been much recent progress in constructing cryptosystems that maintain their security without requiring uniform randomness and perfect secrecy. These schemes are motivated by a diverse set of problems such as providing resilience to side-channel leakage, using weak physical sources of randomness as secret keys, and allowing deterministic encryption for high-entropy messages. The study of these problems has significantly deepened the authors' understanding of how randomness is used in cryptographic constructions and proofs. Nevertheless, despite this progress, some basic and seemingly achievable security properties have eluded their reach. For example, they are unable to prove the security of basic tools for manipulating weak/leaky random sources, such as pseudo-entropy generators and seed-dependent computational condensers.