Decipherment means analyzing and understanding an illegible or incomprehensible script . It is important both in cryptology when deciphering encrypted ciphertexts and in archeology when indexing texts that are written in an unknown language or script , as well as in linguistics , literary studies and palaeography .
Deciphering in cryptology
In cryptology is deciphering a cryptanalytic technique , consisting of a ciphertext without knowledge of the key, the clear text wins. The deciphering of a ciphertext is also referred to as “ breaking ” or colloquially as “cracking” (see also: code breaker ; English codebreaker ).
The decipherment is offset by the decryption of a ciphertext by the authorized recipient. He is in possession of the key. With it he can decipher. Deciphering is not necessary.
In addition, the cryptanalysis considers the weaknesses of the encryption methods used . Those methods that are found to be unsuitable for secure encryption are referred to as "broken". Famous examples of broken historical encryption are the ADFGX method used in World War I and the ENIGMA machine in World War II .
- Famous cryptanalysts
- William Friedman - father of American cryptology
- Friedrich Wilhelm Kasiski - broke the Vigenère cipher
- Dillwyn Knox - one of the first British to crack the German Enigma machine
- Georges Painvin - broke the German ADFGX process during World War I.
- Marian Rejewski - laid the foundations for breaking the Enigma as early as 1932
- Claude Shannon - formulated the maxim "The enemy knows the system used"
- Alan Turing - developed the cryptanalytic "cracking machine" named after him against the Enigma
- Bill Tutte - clarified the German key addition ( Lorenz SZ 40 )
- Gordon Welchman - improved the Turing bomb by developing the diagonal board
Decipherment in archeology and linguistics
In archeology , the term “ decryption ” is also used as a synonym for decipherment and is understood to mean the analysis of an old, no longer known script . In archeology, the document to be deciphered has often not been encrypted to prevent the uninitiated from reading, but the meaning of the text or the ability to read it has been forgotten over time.
- Examples of ancient writings
- The cuneiform scripts in their Sumerian, Akkadian, Elamite and old Persian forms
- The Indusschrift
- The Egyptian hieroglyphics
- The Luwian hieroglyphic script
- The Indusschrift
- The linear font A
- The linear font B
- The Maya script
- The script of the Olmecs
Famous documents already deciphered or still awaiting decipherment:
- Famous decipherers of ancient writings
- John Chadwick
- Jean-François Champollion
- Georg Friedrich Grotefend
- Edward Hincks
- Yuri Knorosow
- Michael Ventris
- Deciphering the Rosette Stone
- Deciphering the Ring of Paußnitz
- Cryptography with applications , slides (PDF; 1.28 MB)
- Cryptographic terms
- Cryptology by Tomy Imboden PDF; 0.8 MB
- Overview and history of cryptology
- Austin Simmons: The Cipherment of the Franks Casket (PDF; 2.16 MB)
- Friedrich L Bauer: Deciphered secrets. Codes and ciphers and how to break them. Springer, Berlin / Heidelberg 1995.
- Ernst Doblhofer : The decipherment of ancient scripts and languages . Reclam, Stuttgart 1993. ISBN 3-15-008854-2 .
- Gero von Wilpert : Specialized Dictionary of Literature (= Kröner's pocket edition . Volume 231). 6th, improved and enlarged edition. Kröner, Stuttgart 1979, ISBN 3-520-23106-9 , keyword: "Handschrift".
- High Command of the Wehrmacht: General key rules for the Wehrmacht . Berlin 1944, p. 5f. Accessed: August 26, 2010. PDF; 0.9 MB .