Speaker
Description
We construct a novel code-based blind signature scheme, using the Matrix Equivalence Digital Signature (MEDS) group action. The scheme is built using similar ideas to the Schnorr blind signature scheme and CSI-Otter, but uses additional public key and commitment information to overcome the difficulties that the MEDS group action faces: lack of module structure (present in Schnorr), lack of a quadratic twist (present in CSI-Otter), and non-commutativity of the acting group. We address security concerns related to public key validation, and prove the security of our protocol in the random oracle model, using the security framework of Kastner, Loss, and Xu, under a variant of the Inverse Matrix Code Equivalence problem and a mild heuristic assumption. We also discuss alternative techniques for constructing a code-based blind signature and consider possible parameter sets and corresponding performance metrics.