PackX

PackX is a Rust library for cryptographically committing 128-byte data segments to a public key. Designed for TAPEDRIVE, it requires node operators to store unique nonce values derived from their pubkey instead of the actual data, while enabling verifiable reconstruction with a specified difficulty.

Usage

• solve(pubkey, data, difficulty) -> Option<Solution> - Generate a solution containing a u64 bump, 16 u8 seeds, and 128 u8 nonces for a 128-byte data segment, meeting the specified difficulty (leading zeros in the hash of the serialized solution).
• verify(pubkey, data, solution, difficulty) -> bool - Verify the solution against the public key, data segment, and difficulty.
• unpack(pubkey, solution) -> [u8; 128] - Reconstruct the original data from the solution and public key.

Example

use packx::{solve, verify, unpack};
use rand::thread_rng;

let mut rng = thread_rng();
let mut pubkey = [0u8; 32];
let mut data = [0u8; 128];
rng.fill_bytes(&mut pubkey);
rng.fill_bytes(&mut data);
let difficulty = 8; // Example difficulty (8 leading zeros in solution hash)

// Find a solution that matches the data and meets the difficulty
let solution = solve(&pubkey, &data, difficulty).expect("Failed to find solution");

// Verify the solution
assert!(verify(&pubkey, &data, &solution, difficulty));

// Reconstruct the original data
let unpacked_data = unpack(&pubkey, &solution);
assert_eq!(unpacked_data, data);

Notes

• Storage overhead: 152 bytes per 128-byte segment (~1.1875:1 ratio).
• Difficulty: The difficulty is the number of leading zeros in the Keccak256 hash of the serialized solution (152 bytes). Higher difficulties require more computation to find a valid solution.
• Parallelization: The library supports parallel nonce searches via find_nonce and solve_with_seed, which can be used with libraries like Rayon for performance optimization.
• Solana Compatibility: The library uses a compute_hash function that supports both Solana’s keccak::hashv (with the solana feature) and the sha3 crate for non-Solana environments.