Casper is a proof-of-stake protocol for Ethereum that is being developed by the Ethereum Foundation. It is designed to be more scalable and energy-efficient than the existing proof-of-work protocol, and to provide stronger security guarantees.
Casper is named after the friendly ghost, because it is intended to be a Friendly Finality Gadget (FFG). An FFG is a mechanism by which a blockchain can achieve consensus without the need for a centralized authority.
Casper is currently in development and is not yet live on the Ethereum network. When it is ready, it will be implemented as a smart contract on the Ethereum blockchain.
The Casper protocol works by requiring users to stake their ETH in order to validate blocks. validators are then chosen pseudo-randomly to create new blocks, and they are rewarded for their work with a portion of the fees from transactions included in the blocks they create.
If a validator attempts to cheat, they will lose their staked ETH. This provides an incentive for validators to act honestly and creates a disincentive for dishonest behavior.
The Casper protocol is intended to be more scalable than proof-of-work, as it does not require computational power in order to validate blocks. This should result in lower transaction fees and faster transaction times.
In addition, the Casper protocol is designed to be more energy-efficient than proof-of-work, as it does not require energy-intensive mining operations.
The Casper protocol is also intended to provide stronger security guarantees than proof-of-work. In particular, Casper aims to prevent so-called “nothing at stake” attacks, in which a validator could theoretically validate multiple competing chains simultaneously in order to maximize their chances of receiving a reward.
Casper is still in development and has not yet been implemented on the Ethereum network. However, when it is ready, it has the potential to improve scalability, efficiency, and security for the Ethereum network.