International Association
for Cryptologic Research

Encryption and compression are frequently used together in both network and storage systems, for example in TLS. Despite often being used together, there has not been a formal framework for analyzing these combined systems; moreover, the systems are usually just a simple chaining of compression followed by encryption. In this work, we present the first formal framework for proving security in combined compression-encryption schemes and relate it to the traditional notion of semantic security. We call this entropy-restricted semantic security. Additionally, we present a new, efficient cipher, called the squeeze cipher, that combines compression and encryption into a single primitive and provably achieves our entropy-restricted security.