Description
I will present our key-recovery attack on the ACDGV public-key encryption scheme proposed at ASIACRYPT 2024 by Aragon, Couvreur, Dyseryn, Gaborit, and Vinçotte. The secret key is a Gabidulin code hidden by appending random rows and columns and by left- and right-multiplication with invertible matrices. Our attack exploits the resulting algebraic structure to recover an equivalent secret key. It improves on the previously known distinguisher and breaks several of the proposed parameter sets. I will conclude with a brief discussion of subsequent work by Le (ePrint 2026/972), which takes a different approach and gives a substantially more efficient attack, breaking all of the proposed parameter sets.