[FARA 68]

Ladislas Farago:

The Broken Seal: "Operation Magic" and the Secret Road to Pearl Harbor

New York, Bantam Books, 1968.

[FEFISH 87]

U.Feige,A.Fiat,A.Shamir:

Zero-knowledge proofs of identity in: Proceedings of the 19th ACM Symposium on the Theory of Computing

 New York, ACM Press,1987.

[FIGL 26]

A. Figl:

Systeme des chiffrierens

Verlag von Ulr. Mosers Buchhandlung, Graz, 1926.

[FREUD 00]

Freud Róbert, Gyarmati Edit:

Számelmélet

Nemzeti Tankönyvkiadó, Budapest, 2000.

[FRIED 76/1]

William F. Friedman:

Elements of Cryptanalysis

Laguna Hills, Aegean Park Press, 1976.

[FRIED 76/2]

William F. Friedman:

Elements Military Cryptography

Laguna Hills, Aegean Park Press, 1976.