A device built by Marian Rejewski that automated the calculations relating to the working of Enigma and made it possible to determine the current key within a dozen or so minutes.
The sources date its creation differently: to 1934 or 1936.1,2
More in the operation card: Breaking Enigma.
Sources
- Internal Security Agency, Marian Rejewski: in the service of Polish cryptology (ABW Publishing House, Wiązowna 2022, ISBN 978-83-964225-4-5) (in Polish)
- Foreign Intelligence Agency, Enigma decryption
Checked: 4 November 2026