Cryptology ePrint Archive: Report 2021/1620

Unicity distance of the Zodiac-340 cipher

Joachim von zur Gathen

Abstract: In December 2020, David Oranchak, Jarl Van Eycke, and Sam Blake solved a 51-year old mystery: the Zodiac cipher of 340 symbols. Blake (2021) explains their solution. The correctness of their solution has not been seriously doubted, and here we give a further argument in its favor: the unicity distance of the cipher's system is at most 152.

Category / Keywords: secret-key cryptography / historical cryptography, Zodiak cipher, cryptanalysis, unicity distance

Date: received 12 Dec 2021

Contact author: gathen at bit uni-bonn de

Available format(s): PDF | BibTeX Citation

Version: 20211214:094110 (All versions of this report)

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