Cryptanalysis of secure arithmetic coding based on interval swapping

Arithmetic coding is prevalent in compression for its remarkable performance, and it is also explored to design encryption schemes offering compression and secrecy simultaneously. Joint compression and encryption is a quite efficient and practical way to protect large volume of data, especially multimedia data, and numerous cryptosystem based on arithmetic coding have been proposed in recent years. In this paper, we present a new classification of secure arithmetic coding algorithms according to the selection of secret information. Then we analyze the security of encryption schemes based on interval swapping. We propose a simple yet efficient attack that could disclose the keystream that is used to make interval swapping decision. The attack works in static and content-based models of arithmetic coding.