Proof-of-Elapsed Time (PoET)

• Is being used in the project Hyperledger Sawtooth which is a modular blockchain suite developed by Intel, which uses this new consensus algorithm called Proof-of-Elapsed Time (PoeT).
• PoET uses new secure CPU instruction, which is more and more available in new processors like Intel builds. With these instructions, PoET ensures a safe and random selection of a so-called  “leader”. This can be compared with Bitcoin mining, in which the miners compete for a one-time access to write the blockchain. Other than Bitcoin’s proof algorithm, PoET doesn’t need specialised mining hardware.
• To become a leader, every “validator” – which equals to a node or a miner – needs to use the secure CPU instruction to request a wait time. The validator with the shortest wait time will be elected as a leader. Like every good mining algorithm PoET works like a lottery with the price to get write access to the blockchain.
• Other than with cryptocurrencies there is no reward for the leader. It is just part of running the software. So there will be no energy-burning competition like in cryptocurrencies. Every node simply can use its CPU – as long as it is a new model and, maybe, from Intel – to participate in the leader selection for no costs.
• To date, Sawtooth is tested in several applications. It is tested to record the journey of seafood from the ocean to the table, using IoT sensors, and track ownership, possession, and parameters through the whole supply chain, from the fisherman to the supermarket. The buyer can access a complete and trustless record of the whole live chain of the seafood. This use case in supply chain and product history is increasingly discussed for Blockchains.
• Sawtooth is also tested to streamline the process of transferring bonds. The developers created a user interface to track and transfer bonds. With this users can manage a whole portfolio of bonds on the blockchain. Another use case of Sawtooth currently tested are digital assets. The developers built a platform for managing digital asset ownership on the Sawtooth blockchain, which could be able to manage a wide scope of digital assets. The connecting dot between this application of Sawtooth seems to be the marketplace for digital assets of any kind which is built in the blockchain and already has a graphical interface for users.