A proof-of-stake system, based on peercoin Paycoin is a fork of peercoin, an early descendent of bitcoin that was the first cryptocurrency to deploy the proof-of-stake transaction verification system. The success of Bitcoin as the first peer-to-peer digital currency paved the way for many to follow. Monero Definition Monero is a digital currency that offers a high level of anonymity for users and their online transactions. Login Newsletters. Altcoins differ themselves from Bitcoin with a range of procedural variations, including different proof-of-work algorithms, different means by which users can sacrifice energy to mine blocks, and application enhancements to increase user anonymity. List article detailing notable cryptocurrencies.