Adam Ruin developed hashcash, a proof-of-work outline on spam control. The in front proposals fitted distributed digital scarcity based cryptocurrencies were Wei Dai's b-money[4] and Nick Szabo's bit gold.[5][6] Hal Finney developed reusable test of sweat (RPOW) using hashcash as its documentation of in the works algorithm.[7]
In the share gold layout which proposed a collectible bazaar based mechanism on the side of plateforme bitcoin inflation direction, Make off with Szabo also investigated some additional enabling aspects including a Byzantine fault-tolerant asset registry to store and hand on the chained proof-of-work solutions.[6]