What is proof of Elapsed Time?

Proof of Elapsed Time (PoET) is a proof of work consensus protocol designed specifically for businesses. The way it works is by randomly selecting a participating node, allowing those not selected to “rest” their Central Processing Units (CPUs) or getting them to work on different things while waiting for their turn. This allows for a reduction in energy consumption in comparison to other consensus protocols, such as Bitcoin’s proof of work, which requires miners to continually contribute to processing transactions across the network.

PoET was developed by Intel’s Hyperledger Sawtooth and requires miners to sign up and wait to be assigned a block in a randomly calculated time period. When selected, the miner’s computer “wakes up” and begins to process its assigned block. It then informs the network that it has processed the block and updates the ledger. This waiting period is what gives the consensus its name and is part of the work effort required to deter bad actors from manipulating the network due to the resource commitment needed.

The use case for PoET is businesses, such as those involved in supply chains and food traceability, that want to create their own distributed ledgers that are accessible by third parties.  This means the requirements for proof of work are less than those needed by Bitcoin as it does not need to continually validate the network in the same way. This allows for the downtimes that result in comparatively reduced energy consumption. 

Miners need to acquire a membership certificate to participate in the network, which means gatekeepers are able to improve the security of the network. Bitcoin on the other hand can be mined by anyone with no certificate needed, so the ledger needs to be watched more closely to ensure the legitimacy of the entries.