Paper 2021/625

Plactic key agreement

Daniel R. L. Brown

Abstract

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: Added 2 references: Rabi-Sherman, 1993, for key agreement based on associative binary operation; Cain-Gray-Malheiro for some properties of plactic monoid (potentially relevant to plactic key agreement, details pending).