Paper 2020/1492

Automated ciphertext-only attack on the Wheatstone Cryptograph and related devices

Thomas Kaeding
Abstract

We examine some historical proto-mechanical cryptographic devices, such as the Wheatstone Cryptograph, that employ revolving clock hands or rotating concentric disks. The action of these “cipher clocks” can be factored into a stream cipher followed by a monoalphabetic substitution. This allows us to perform a stochastic hill-climbing attack to break the substitution. The attack maximizes a fitness that measures how well a decryption of the substitution cipher resembles an encryption of the stream cipher alone.

Metadata
Available format(s)
PDF
Publication info
Preprint.
Keywords
Wheatstone Cryptograph Wadsworth cipher disk Urkryptografen cipher clock hill-climbing attack
Contact author(s)
kaeding @ blackswan duckdns org
History
2022-11-30: revised
2020-11-29: received
See all versions
Short URL
https://ia.cr/2020/1492
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2020/1492,
      author = {Thomas Kaeding},
      title = {Automated ciphertext-only attack on the Wheatstone Cryptograph and related devices},
      howpublished = {Cryptology ePrint Archive, Paper 2020/1492},
      year = {2020},
      note = {\url{https://eprint.iacr.org/2020/1492}},
      url = {https://eprint.iacr.org/2020/1492}
}
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