Consensus algorithms are an essential part of the blockchain technology. They are used to ensure that the “main chain” at every node of the network is the same. This results in a consistent state of the blockchain. According to Andreas Aandopoulos (a tech entrepreneur), consensus algorithms have formed a new discipline in the field of computer science.
Proof of Elapsed Time (PoET) is an efficient alternative to
However, in PoET, a separate random timer that operates independently at every node determines whether or not that node creates the new block of the blockchain and gets the reward. This randomization also ensures that every node is equally likely to be the winner.
The PoET algorithm is for permissioned blockchain networks. That is, a special verification is required from a node when it tries to join the network. This verification is achieved using Intel’s
The network operates in the following way:
A node downloads the PoET code and generates an attestation (key) for the code using SGX.
The node forwards this key when requesting to join the network. The nodes that are already a part of the network verify this key.
The new node now has its own timer object which is initialized to a random value. This randomness is guaranteed by the code protection offered by SGX.
All nodes are initialized with a random time; the first one to expire gets to be the winner. This means that it creates a new block, attaches it to the current blockchain, and gets the reward. Then, the nodes are initialized again.