Can a Validator in a PoS System Execute a Successful Double-Spend without a Majority Stake?
No, a single validator cannot successfully execute a double-spend. While they can propose a block that contains a conflicting transaction, the network's consensus mechanism requires a supermajority of validators to attest to and finalize a block.
Without the majority stake, their malicious block will be rejected, and they risk being slashed for proposing an invalid or conflicting block.
Glossar
Validator
Role ⎊ A validator is a critical network participant in a Proof-of-Stake blockchain responsible for proposing, verifying, and attesting to new blocks of transactions to maintain consensus and secure the distributed ledger.
Consensus Mechanism
Efficacy ⎊ : The mechanism's efficacy is measured by its ability to achieve agreement on transaction ordering and state transition while maintaining a high degree of decentralization and finality.
PoS System
Architecture ⎊ This consensus mechanism relies on a set of validators who lock up a quantity of the native cryptocurrency as collateral to gain the right to propose and attest to new blocks on the chain.
Majority
Consensus ⎊ Majority, within decentralized systems, denotes the agreement threshold required to validate transactions or state changes on a blockchain, influencing network security and operational efficiency.