Paper 2020/302
Slippery hill-climbing technique for ciphertext-only cryptanalysis of periodic polyalphabetic substitution ciphers
Thomas Kaeding
Abstract
We present a stochastic method for breaking general periodic polyalphabetic substitution ciphers using only the ciphertext and without using any additional constraints that might come from the cipher’s structure. The method employs a hill-climbing algorithm for individual key alphabets, with occasional slipping down the hill. We implement the method with a computer and achieve reliable results for a sufficiently long ciphertext (150 characters per key alphabet). Because no constraints among the key alphabets are used, this method applies to any periodic polyalphabetic substitution cipher.
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- Published elsewhere. Minor revision. Cryptologia
- DOI
- 10.1080/01611194.2019.1655504
- Keywords
- periodic polyalphabetic substitution cipherhill-climbingslippery hill-climbingcryptanalysisVigenèreQuagmire
- Contact author(s)
- hippykitty @ protonmail com
- History
- 2020-04-26: revised
- 2020-03-12: received
- See all versions
- Short URL
- https://ia.cr/2020/302
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2020/302,
author = {Thomas Kaeding},
title = {Slippery hill-climbing technique for ciphertext-only cryptanalysis of periodic polyalphabetic substitution ciphers},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/302},
year = {2020},
doi = {10.1080/01611194.2019.1655504},
url = {https://eprint.iacr.org/2020/302}
}
