The Hyperledger Sawtooth project introduced a new consensus mechanism called proof-of-elapsed-time or PoET. Hyperledger deals mostly with permissioned blockchains, chains in which only a specified number of participants are allowed on the network, similar to PoA chains.
The basic approach is simple:
- Each node must wait a random amount of time
- The first node to stop waiting gets to create a block
There are two things that we must be able to do for this to work. First, we must be able to verify that the waiting time for all participants was actually random, or else a simple attack would be to pretend to wait a random time and then just immediately create a new block. Second, it must be verifiable that not only was the length of time chosen random, but that the node actually waited the full period of time before acting.
The solution to these issues comes from Intel (who created the PoET algorithm), and relies on special CPU instructions to ensure that only trusted code is run...