ATMcash is a cryptocurrency based on proofs of capacity with additions, clarification, and formatting by ATMcash technical team post-development. The team propose a decentralized cryptocurrency called ATMcash, which is based on a blockchain ledger similar to that of Bitcoin, but where the wasteful proofs of work are replaced by efficient proofs of capacity, recently introduced by Dziembowskiet al. Instead of requiring that a majority of the network’s computing power is controlled by honest miners (as in Bitcoin), the currency requires that honest miners dedicate more net disk capacity than a potential adversary. In ATMcash, once a miner has dedicated and initialized some capacity, participating in the mining process is very cheap. A new block is added to the chain every fixed period of time, and in every period a miner just has to make a small number of lookups to the stored capacity to check if she “wins”, and thus can efficiently add the next block to the chain and get the mining reward.