Report on the First DES Fixed Points for Non-Weak Keys: Case-Study of Hacking an IoT Environment
Norbert Tihanyi · IEEE Access · 2022
Fixed points can be defined asEK(P) =Pfor a keyKand plaintextPwhereEis the encryption function. For the Data Encryption Standard (DES) algorithm there are four weak keys, such thatEK(EK(P)) =Pfor allP. For each weak key there are 232fixed points where all the sixteen round keys are the same. While there is a high probability that DES has fixed points for non-weak keys, nobody has reported such (P,K) pairs until now. Performing 1000 × 256DES encryption operations using 256 Xlinix Spartan-6 parallel cost-effective FPGAs we answer the question of Judy H. Moore and Gustavus J. Simmons: we report the first known DES fixed points where all round keys are different. A case study is presented where an IoT based Sensor Device Authentication Algorithm (SDAA) can be exploited using DES fixed points.