Extending Coggia-Couvreur attack on Loidreau's rank-metric cryptosystem (Q2068390)

The paper extends the polynomial time key-recovery attack on Loidreau's rank-metric scheme, based on rank-metric codes, for some parameters. The idea was originally proposed by \textit{D. Coggia} and \textit{A. Couvreur} [Des. Codes Cryptography 88, No. 9, 1941--1957 (2020; Zbl 1453.94163)] and proven for dimension parameter \(\lambda = 2\). The author succeeds in extending it to \(\lambda >2\) by noticing that identifying the non-random structure so-called ``distinguisher'' of the dual of the public code, is possible for all values of \(\lambda \geq 2\).