Curiously, finding cycles in graphs defined by siphash-2-4 is exactly what my Cuckoo Cycle Proof-of-Work is about [1]. Furthermore, the most efficient algorith

Curiously, finding cycles in graphs defined by siphash-2-4 is exactly what my Cuckoo Cycle Proof-of-Work is about [1]. Furthermore, the most efficient algorithm for solving it, by edge-trimming, also suggests an interesting memory-hard PBKDF, where you hash the edge bitmap after a small fixed number of edge trimming rounds. [1] https://github.com/tromp/cuckoo https://github.com/tromp/cuckoo