A private architecture for public networks

We discuss possible standards for ISDN security that allow data transmitted over ISDN to be encrypted so that only the intended receiver can decipher it. This will make the public ISDN behave like a private network and allow ISDN to be a solution in applications that require authentication, privacy and confidentiality. The authors describe the properties of data encryption schemes required to impose a secure architecture upon the public network. Furthermore, the paper describes the software and hardware realization concepts which can be embedded into the ISDN customer premises equipment (CPE) and require no software upgrades of the switching equipment. This will make the public ISDN network look like a private network to the security conscious user.