## Cryptology ePrint Archive: Report 2021/1494

On the efficiency of a general attack against the MOBS cryptosystem

Christopher Battarbee and Delaram Kahrobaei and Dylan Tailor and Siamak F. Shahandashti

Abstract: All instances of the semidirect key exchange protocol, a generalisation of the famous Diffie-Hellman key exchange protocol, satisfy the so-called telescoping equality''; in some cases, this equality has been used to construct an attack. In this report we present computational evidence suggesting that an instance of the scheme called `MOBS (Matrices Over Bitstrings)' is an example of a scheme where the telescoping equality has too many solutions to be a practically viable means to conduct an attack.

Category / Keywords: public-key cryptography / key-exchange, semidirect product, Boolean matrices