In order to create a new type of bitcoin coin, either a new blockchain must be built, or an existing protocol must be updated in order to create a fork or new version. Most of these "alternative currencies" are forks of Bitcoin technology. Existing crypto coins can produce more coins only through a process known as "mining," in which the miner receives a transaction fee (a new currency) for contributing to the underlying blockchain algorithm by solving a cryptographic puzzle.

The mining industry is a competitive sector that requires a substantial amount of processing power. Cryptocurrencies such as Bitcoin have a limited supply, which implies that the total number of coins in circulation will never be infinite. Some do not have a cap, but limit the number of new coins issued each year.