1. ANSI X9.17-1985: Financial Institution Key Management (Wholesale), 1985.
2. ANSI X12.42-198x: EDI Security Structures and Cryptographic Service Message Transaction Set, 1989.
3. Lect Notes Comput Sci;F. Bauspieß,1990
4. Burrows, M.; Abadi, M.; Needham, R.: A Logic of Authentication, DEC System Research Center Report 39, 1990.
5. CCITT Draft Recommendation X.509: The Directory-Authentication Framework, 1987.