Kryha

This article deals with the cipher machine, for information on the river of the same name in Ukraine, see Kryha (river) .

Kryha encryption machine

Drawing for US patent

The Kryha is a mechanical encryption machine with a fixed periodic key developed by Alexander von Kryha (1891–1955) in the 1920s .

Kryha's idea was to automate the twisting of a cipher disk with the help of a spring drive . In 1926 the device came on the market as the Kryha cipher machine .

Cryptanalysis

The security of the machine was checked by the mathematician Georg Hamel , who calculated the size of the key space.

In 1933 was William F. Friedman , together with Solomon Kullback , Frank Rowlett and Abraham Sinkov an encrypted message with Kryha consisting of 1,135 characters in two hours and 41 minutes decipher . Despite the weakness of the machine, which was proven by this, it was still in use until the 1950s.

literature

• Klaus Schmeh : Code breakers versus code makers. The fascinating story of encryption. 2nd Edition. W3L-Verlag, Herdecke et al. 2008, ISBN 978-3-937137-89-6 .

Web links

Commons : Kryha  - collection of images, videos and audio files

• Pictures of the inner workings of a mechanical Kryha (English)
• Alexander von Kryha, "Coding machine", US Patent 1,744,347 (filed February 20, 1925)
• The Kryha encryption machine: One of the biggest flops in cryptology history ; at datensicherheit.de by Klaus Schmeh ; refers to Cryptologia , edition 4/2010
• Kryha Encryption Machines Sales brochure with pictures of its three machines. Retrieved May 19, 2015.
• The Kryha Cipher Machine (English). Retrieved March 21, 2016.
• The Kryha Cipher Machine 1929 (English). Retrieved May 19, 2015.

Individual evidence

1. ↑ Lambros D. Callimahos : QED-2 Hours, 41 Minutes. (PDF; 857 kB) National Security Agency , Technical Journal Articles, Vol. XVIII, No. 4, 1973, accessed May 9, 2016 .