Proof-of-Stake Cryptographic Mechanisms

Proof-of-Work (PoW) secures blockchains through computational expenditure: miners race to find a hash below a target, and the winner appends the next block. This burns electricity proportional to network security. Proof-of-Stake (PoS) replaces compute with economic stake — validators lock up cryptocurrency as collateral, and the protocol selects block proposers in proportion to their stake. Ethereum's transition from PoW to PoS (The Merge, September 2022) reduced energy consumption by over 99.9%.

In Ethereum's PoS (Gasper consensus), validators stake 32 ETH by sending a deposit transaction to a smart contract on the execution layer. This deposit includes a BLS public key (the validator's identity), a withdrawal credential, and a signature proving key ownership. The deposit contract emits a log event; the consensus layer reads these logs and queues validators for activation after a delay (roughly 12-24 hours under normal conditions). The 32 ETH collateral is locked until withdrawal is enabled.