uhash-core

UniversalHash v4 algorithm - a democratic proof-of-work hash function designed for mobile-friendly mining.

v0.2.0 - Full spec compliance with UniversalHash v4 specification.

Features

Spec-compliant: Implements UniversalHash v4 specification exactly
Mobile-optimized: 4 parallel chains match typical phone core count
Memory-hard: 2MB scratchpad (4x512KB) prevents GPU advantage
ASIC-resistant: Triple primitive rotation (AES + SHA256 + BLAKE3)
No-std compatible: Works in WASM and CosmWasm environments
Hardware accelerated: Uses ARM/x86 crypto intrinsics when available

Performance

Device	Native	WASM
Mac M1/M2	~1,100-1,400 H/s	~400 H/s
iPhone 14 Pro	~594 H/s	~200 H/s
Galaxy A56 5G	~185 H/s	~50 H/s

Phone-to-desktop ratio: 1:1.2 to 1:3.8 depending on device (target: 1:3-5)

Usage

use uhash_core::{UniversalHash, meets_difficulty};

// Create a reusable hasher (allocates 2MB scratchpad)
let mut hasher = UniversalHash::new();

// Input format: header || nonce (nonce is last 8 bytes)
// Typical mining format: epoch_seed (32B) || miner_address (20B) || timestamp (8B) || nonce (8B)
let input = b"epoch_seed_here_32bytes_long!miner_address_20Btimestmpnonce123";
let hash = hasher.hash(input);

// Check if hash meets difficulty (number of leading zero bits)
if meets_difficulty(&hash, 20) {
    println!("Found valid proof!");
}

Input Format

The algorithm extracts the nonce from the last 8 bytes of input for seed generation:

input = header || nonce
        ^^^^^^    ^^^^^
        any len   8 bytes (little-endian u64)

This allows the spec-compliant seed generation: BLAKE3(header || (nonce ⊕ (chain × golden_ratio)))

Algorithm Specification

Parameter	Value	Description
Chains	4	Parallel computation chains
Scratchpad	512KB × 4	Per-chain memory
Total Memory	2MB	Fits in phone L3 cache
Rounds	12,288	Iterations per chain
Block Size	64 bytes	Memory access granularity
Primitives	AES, SHA256, BLAKE3	Rotated each round

Spec Compliance (v0.2.0+)

Seed generation: BLAKE3(header || (nonce ⊕ (c × 0x9E3779B97F4A7C15)))
Primitive rotation: (nonce + chain + round + 1) mod 3
Address calculation: state[0:8] ⊕ state[8:16] ⊕ rotl64(round, 13) ⊕ (round × 0x517cc1b727220a95)
Write-back: Same address as read (creates read-after-write dependency)
Finalization: BLAKE3(SHA256(XOR of all chain states))

Cargo Features

std (default): Enable standard library support
parallel (default): Enable parallel chain processing via rayon

For no_std environments (WASM, CosmWasm):

[dependencies]
uhash-core = { version = "0.2", default-features = false }

Demo App

A cross-platform native benchmark app is included in the demo/ directory. Built with Tauri v2.

cd demo/src-tauri

# Desktop (macOS/Windows/Linux)
cargo tauri build

# iOS
cargo tauri ios init && cargo tauri ios build

# Android (ARM64)
cargo tauri android init && cargo tauri android build --target aarch64

See demo/README.md for detailed build instructions.

Changelog

See CHANGELOG.md for version history.

License

Unlicense - Public Domain

uhash-core 0.2.0