qp-poseidon

Substrate-compatible Poseidon hash implementation for the Polkadot ecosystem. This crate wraps qp-poseidon-core and adds Substrate-specific functionality including codec traits and specialized storage operations.

Features

• Substrate integration: Implements required traits for use in Substrate/Polkadot projects
• Codec support: Implements Encode, Decode, and TypeInfo traits from parity-scale-codec
• Serde support: Optional serialization support via the serde feature
• Storage hashing: Specialized functions for Quantus Network storage operations
• Circuit compatibility: Maintains compatibility with zero-knowledge circuit implementations
• No-std support: Works in constrained environments

Usage

Add this to your Cargo.toml:

[dependencies]
qp-poseidon = { path = "path/to/qp-poseidon/crates/substrate" }

Basic Hashing

use qp_poseidon::PoseidonHasher;

// Hash bytes with circuit-compatible padding
let data = b"hello world";
let hash = PoseidonHasher::hash_padded(data);
println!("Hash: {:?}", hash);

Performance

• Optimized for Substrate's encoding/decoding patterns
• Maintains deterministic behavior across different platforms
• Memory efficient for blockchain storage operations
• Circuit-compatible padding ensures consistency with ZK proofs

Security

• Built on qp-poseidon-core's security guarantees
• Uses standard Substrate codec patterns
• Specialized storage hashing prevents collision attacks

Integration

use qp_poseidon::PoseidonHasher;
use frame_support::pallet_prelude::*;

#[pallet::config]
pub trait Config: frame_system::Config {
    type Hasher: sp_runtime::traits::Hash<Output = sp_core::H256>;
}

// Use PoseidonHasher as the pallet's hasher
impl pallet::Config for Runtime {
    type Hasher = PoseidonHasher;
}

Related Crates

• qp-poseidon-core - The underlying pure cryptographic implementation
• parity-scale-codec - Substrate's encoding library
• plonky3 - The underlying field arithmetic library