Proof of Elapsed Time (PoET) Meaning

Proof of Elapsed Time (PoET) is a Consensus Mechanism developed by Intel for use in Permissioned Blockchains (like Hyperledger Sawtooth). It uses a Lottery System to decide who Wins the right to create the next block. Every Node in the network Requests a Wait Time from a Secure Part of the CPU (called a Trusted Execution Environment or TEE).

The node with the Shortest Wait Time Wins and is allowed to publish the block.The Magic of PoET is that it is Incredibly Energy Efficient. Instead of Mining (PoW), the nodes are simply Sleeping for a few milliseconds.

The TEE (like Intel SGX) ensures that the Wait Time is Truly Random and that the node Actually Waited for the full duration. This provides the Fairness of a lottery without the Waste of a competition, allowing for a Highly Scalable network.PoET is Perfect for Enterprise Use Cases where the participants are Known but Don't Fully Trust Each Other.

It allows a Consortium of Companies to maintain a Shared Ledger with very Low Overhead. Because there is no Mining Fee and the hardware is just Standard CPUs, it is Much Cheaper to run than a public blockchain.

It is a Professional Tool for Business Automation.The Weakness of PoET is its Hardware Dependency. The entire security of the network relies on the Security of the Intel CPU.

If a Vulnerability is found in the TEE (as has happened with Spectre and Meltdown attacks), the entire consensus could be Compromised. This Single Point of Failure is why Public Blockchains (like Ethereum) prefer Software-based Consensus (like PoS) that doesn't rely on a Single Hardware Manufacturer.