Fish (cryptography)

Fish (cryptography)

Fish (sometimes FISH) was the Allied codename for any of several German teleprinter stream ciphers used during World War II. Enciphered teleprinter traffic was used between German High Command and Army Group commanders in the field, so its intelligence value (Ultra) was of the highest strategic value to the Allies. This traffic normally passed over landlines, but as German forces extended their reach out of western Europe, they had to resort to wireless transmission.