Security Analysis of the Digital Transmission Copy Protection Specification

This paper analyzes the secure protocols in the digital transmission copy protection (DTCP) specification. The full authentication protocol in the specification is a combination of the Diffie-Hellman (DH) key exchange algorithm and the digital signature technique. It is claimed that the protocol can prevent “man in the middle” attacks. However, we can apply at least three classical attacks to the protocol. All of them can overthrow the authentication objective. Further, a sender or receiver mismatching is discovered. The receiver mismatching threats the system integrity property of the DTCP specification.