Solana Whitepaper

Abstract

This paper proposes a new blockchain architecture based on Proof
of History (PoH) - a proof for verifying order and passage of time between events. PoH is used to encode trustless passage of time into a ledger - an append only data structure. When used alongside a consensus algorithm such as Proof of Work (PoW) or Proof of Stake (PoS), PoH can reduce messaging overhead in a Byzantine Fault Tolerant replicated state machine, resulting inn sub-second finality times.

This paper also proposes two algorithms that leverage the time keeping properties of the PoH ledger - a PoS algorithm that can recover from partitions of any size and an efficient streaming Proof of Replication (PoRep). The combination of PoRep and PoH provides a defense against forgery of the ledger with respect to time (ordering) and storage. The protocol is analyzed on a 1 gbps network, and this paper
shows that throughput up to 710k transactions per second is possible
with todays hardware.

Introduction

Blockchain is an implementation of a fault tolerant replicated state machine.

Current publicly available blockchains do not rely on time, or make a weak assumption about the participants abilities to keep time [4, 5]. Each node in the network usually relies on their own local clock without knowledge of any other participants clocks in the network.

The lack of a trusted source of time means that when a message timestamp is used to accept or reject a message, there is no guarantee that every other participant in the network will make the exact same choice.

The PoH presented here is designed to create a ledger with verifiable passage of time, i.e. duration between events and message ordering. It is anticipated that every node in the network will be able to rely on the recorded passage of time in the ledger without trust.