Revisiting Meet-in-the-Middle Cryptanalysis of SIDH/SIKE with Application to the $IKEp182 Challenge

We report a break of the \$IKEp182 challenge using a meet-in-the-middle attack strategy improved with multiple SIKE-specific optimizations. The attack was executed on the HPC cluster of the University of Luxembourg and required less than 10 core-years and 256TiB of high-performance network storage (GPFS). Different trade-offs allow execution of the attack with similar time complexity and reduced storage requirements of only about 70TiB.