In cryptology, a hand key is a key process (encryption or decryption process) that, in contrast to a machine key , is not carried out automatically, for example with the help of a rotor cipher machine , but can be done manually, often with pencil and paper.
Until about the time of the First World War , almost only hand keys were used. The German ADFGX process is an important example from this period . Even during the Second World War , when key machines were increasingly being used, not only the German side continued to use manual keying methods to encrypt their secret message traffic . They were especially used when the relevant units did not have a machine key or it was defective. For example, the German Navy used the shipyard key and the reserve manual procedure , while the army used the double-box key as a manual key.
- Friedrich L. Bauer : Deciphered secrets, methods and maxims of cryptography . Springer, Berlin 2000 (3rd edition), ISBN 3-540-67931-6 .
- Heinz Ulbricht: The Enigma cipher machine - deceptive security. A contribution to the history of the intelligence services. Dissertation Braunschweig 2005. PDF; 4.7 MB . Retrieved May 18, 2016.
- Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. 68.