Grin empowers anyone to transact or save modern money without the fear of external control or oppression. Grin is designed for the decades to come, not just tomorrow. Grin wants to be usable by everyone, regardless of borders, culture, skills or access. Grin uses a proof-of-work system called Cuckoo Cycle that searches very large graphs for cycles, i.e. a cyclic path (a path that loops back on itself).