Paper 2021/625

Plactic key agreement

Daniel R. L. Brown, BlackBerry

Plactic key agreement is a new key agreement scheme that uses Knuth’s multiplication of semistandard tableaus from combinatorial algebra. The security of plactic key agreement relies on the difficulty of some computational problems, such as division of semistandard tableaus. Division by erosion uses backtracking to divide tableaus. Division by erosion is estimated to be infeasible against public keys of 768 or more bytes. If division by erosion is the best attack against plactic key agreement, then secure plactic key agreement could be practical.

Note: This version of this eprint includes three revisions suggested by anonymous reviewers (for JMC): (1) a new reference applying semistandard tableaus to cryptography, (2) a critical reminder that unauthenticated key agreement is vulnerable to MITM attacks, and, most importantly, (3) a new attack on plactic key agreement that seems to require doubling the key sizes.

Available format(s)
Public-key cryptography
Publication info
Published elsewhere. Journal of Mathematical Cryptology
key agreement key exchange combinatorics plactic monoid semistandard tableau
Contact author(s)
danibrown @ blackberry com
2022-07-27: last of 5 revisions
2021-05-17: received
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      author = {Daniel R.  L.  Brown},
      title = {Plactic key agreement},
      howpublished = {Cryptology ePrint Archive, Paper 2021/625},
      year = {2021},
      note = {\url{}},
      url = {}
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