Some cryptographic principles of authentication in electronic funds transfer systems

One essential requirement of an Electronic Funds Transfer (EFT) system is that institutions must be able to join together in a common EFT network such that a member of one institution can initiate transactions at entry points in the domain of another institution. The use of such a network is defined as interchange. Cryptographic implementations are developed for such a network in such a way as to keep personal verification and message authentication processes at different institutions completely separate. This is accomplished through the combined use of user-remembered personal identification numbers (PINs), secret system keys, and intelligent secure (bank) cards on which are recorded secret personal cryptographic keys.