On weaknesses of the HDCP authentication and key exchange protocol and its repair

The high-bandwidth digital content protection (HDCP) specification developed by Intel protects encrypted digital content transmitted between the HDCP transmitter and the HDCP receiver. We discovered that the authentication and key exchange (AKE) protocol in the newest HDCP specification v 2.0 fails to prevent against the UKS attack and the impersonation attack. Moreover, this protocol does not demonstrate forward secrecy and key confirmation properties. Based on these findings, we propose a carefully designed variant named SH-AKE. The new protocol satisfies all the security goals not contained in the original AKE protocol with a slight increase in the computational cost.