Evaluation of MPEG-4 IPMP extension

MPEG-4 IPMPX (intellectual property management and protection extension) is the latest ISO standard which provides a flexible framework for protecting MPEG streams. The message mechanism of IPMPX enables interoperability among IPMPX-compliant devices no matter which protection methods are embedded. This paper highlights several problems in the message syntax of IPMPX: the tool delivery message IPMP/spl I.bar/ToolES/spl I.bar/AU is vulnerable to network attack, the authentication message IMP/spl I.bar/Mutual/spl I.bar/Authentication is incapable of defending against forgery attack, and the configuration message IPMP/spl I.bar/SelectiveDecrptionInit is ambiguous and redundant. We propose a number of remedies to those problems, which can be incorporated into a corrigenda to improve the present ISO MPEG-4 IPMP standard.