Secure physical access control with strong cryptographic protection

This paper is focused on the area of physical access control systems (PACs), particularly on the systems for building access control. We show how the application of modern cryptographic protocols, namely the cryptographic proofs of knowledge, can improve the security and privacy protection in practical access control systems. We propose a novel scheme SPAC (Secure Physical Access Control) based on modern cryptographic primitives. By employing the proofs of knowledge, the authentication process gets more secure and privacy friendly in comparison to existing schemes without negative influence on the implementation complexity or system performance. In this paper, we describe the weaknesses of existing schemes, show the full cryptographic specification of the novel SPAC scheme including its security proofs and provide benchmarks on off-the-shelf devices used in real commercial systems. Furthermore we show, that the transition from an old insecure system to strong authentication can be easy and cost-effective.