Yep, like hellojebus said, what you are describing sounds a lot like ripple. They use their own type of consensus algorithm described below. https://ripple.com

Yep, like hellojebus said, what you are describing sounds a lot like ripple. They use their own type of consensus algorithm described below. https://ripple.com/files/ripple_consensus_whitepaper.pdf https://ripple.com/files/ripple_consensus_whitepaper.pdf There are also other coins without mining though. In an abstract sense, mining is just a general term for weighting votes for what are and aren't valid transactions based on 'proof of work'. The required investment of processing power discourages attempts to validate invalidate transactions, since investing work on the wrong version of the chain will inevitably lead to you not getting a block reward unless 51% of the network is controlled by you or somehow decides to follow along in your fraud. https://en.wikipedia.org/wiki/Proof-of-work_system https://en.wikipedia.org/wiki/Proof-of-work_system There are other mechanisms for reaching consensus though. One of the most established is proof of stake, in which validations are weighted based on the coins you own. Notably, Ethereum is working to implement this with Casper by requiring auditable byzantine fault tolerance (detection of both when bad actors are acting as well as who is responsible) and security deposits for each 'vote' to alleviate the 'nothing at stake' problem, punishing bad actors. With this system there will be no unnecessary computations/energy usage, and there's actually more resistance to 51% attacks, since an attackers coins can be burned when they try to attack, leading to an undefined amount of capital required to get 51% of the vote, whereas with proof of work there is a set amount of processing power you could by to take control of the network indefinitely. https://en.wikipedia.org/wiki/Proof-of-stake https://en.wikipedia.org/wiki/Proof-of-stake There are also other systems like DAG distributed ledgers which combine small amounts of proof of work for spam resistance into the transaction process, eliminating the concept of mining and transaction fees all together. DAG ledgers aren't really blockchains at all, but a superset of blockchains, instead of just being a linked list they use an interwoven directed acyclic graph of transactions. Notable cryptocurrencies that use this type of ledger are Iota, RaiBlocks and Byteball Bytes.