Proof of History (PoH)

PoH works on one of the most challenging distributed system problems, i.e., agreement on time. The problem is identifying the sequence of transactions at particular timestamps and determining the correct sequence of events.

PoH uses a high- frequency verifiable delay function to hash incoming events and transactions. Every event has a unique hash and count along with this data structure as a function of real time. This information tells us what event had to come before another event, almost like a cryptographic timestamp giving us a verifiable ordering of events as a function of time. Each node has a cryptographic clock that helps the network agree on the time and order of events without waiting to hear from other nodes. This approach executes the SHA-256 hashing algorithm consecutively to use the output of each round as the connected input to the next round. Leaders control the verification and integration of individual transactions with the prevailing hash. The confirmed transactions are the votes for the consensus algorithm. An additional layer of security is added in this network wherein an invalid hash is generated at random intervals, and those verifiers who validate it are penalized.