On the design of partial encryption scheme for multimedia content

Partial encryption, also named selective encryption, is regarded as a suitable choice for multimedia content encryption because of the properties of time efficiency, format compliance and network compliance. To push it to practical applications, its security should be investigated. However, few works have been done to analyze partial encryption schemes’ security. In this paper, with respect to the existing attacks (cryptographic attack, replacement attack and statistical model based attack), a partial encryption model is presented, together with some secure encryption principles. Furthermore, based on the principles, a partial encryption scheme in wavelet domain is proposed, and its performances are evaluated, which proves the principles suitable for designing or evaluating multimedia encryption schemes.