Abstract This paper shows new card-based cryptographic protocols using private operations that are secure against malicious players. Physical cards used in instead of computers. Operations a player executes place where the other players cannot see called operations. Using several operations, calculations two variable Boolean functions and copy were realized with minimum number cards. Though ver...

We consider the so called “cryptographic protocols” whose aim is to ensure some security properties when communication channels are not reliable. Such protocols usually rely on cryptographic primitives. Even if it is assumed that the cryptographic primitives are perfect, the security goals may not be achieved: the protocol itself may have weaknesses which can be exploited by an attacker. We sur...

We present a general framework for representing cryptographic protocols and analyzing their security. The framework allows specifying the security requirements of practically any cryptographic task in a unified and systematic way. Furthermore, in this framework the security of protocols is preserved under a general protocol composition operation, called universal composition. The proposed frame...