Description

Solana Proof of History (PoH) Simulation in RustThis project is a simplified simulation of Solana’s Proof of History (PoH) implemented in Rust.

It demonstrates how PoH creates a cryptographic hash chain to sequence transactions, providing a verifiable, tamper-resistant record of time and order. The simulation is designed for learning purposes, helping me understand Solana’s PoH mechanism while practicing Rust programming concepts like structs, ownership, and external crates.

Overview

This project simulates Solana’s Proof of History (PoH), a key component of Solana’s high-throughput blockchain. PoH generates a sequential SHA-256 hash chain to timestamp and order transactions, reducing network communication by enabling local verification. The simulation creates a PoH chain, embeds mock transactions, and verifies the chain’s integrity, mimicking Solana’s approach in a simplified way. It’s built in Rust to leverage its performance and safety features, making it an excellent learning tool for both Solana and Rust.

What is Proof of History?

Proof of History (PoH) is a cryptographic technique used by Solana to create a verifiable sequence of hashes, acting as a decentralized clock. Each hash depends on the previous one, and transactions can be embedded into the chain to prove their order and timing. Key properties:

• Difficult to Produce: Generating the hash chain is computationally intensive (sequential hashing).
• Easy to Verify: Checking the chain’s integrity is fast, requiring only a few hash computations.
• Role in Solana: PoH orders transactions in the Transaction Processing Unit (TPU)’s PoH Stage, reducing communication overhead and supporting Solana’s 50,000+ transactions per second (TPS).

Project Features

• Generates a sequential SHA-256 hash chain starting with a “genesis” seed.
• Embeds mock transactions (as strings) into the chain, simulating Solana’s transaction inclusion.
• Supports empty “ticks” (hashes without transactions) to mark time passage.
• Verifies the chain’s integrity to demonstrate PoH’s tamper-resistant design.
• Outputs the chain’s contents (counter, hash, transaction) for easy visualization.
• Includes a tampering test to show verification failure if the chain is altered.