PQC Wallet

PQC Wallet is Vaulkyrie’s post-quantum-oriented wallet mode. It uses hash-based one-time signatures rather than Ed25519 signatures for spend authorization. The implementation is inspired by Blueshift Labs’ Winternitz-based Solana work and adapts the idea into Vaulkyrie’s browser wallet and vaulkyrie-core program model.

What it protects against

Classical Solana wallets rely on Ed25519. A sufficiently capable quantum adversary could threaten elliptic-curve signatures. Hash-based one-time signatures are a different family of signatures whose security rests on hash preimage resistance. PQC Wallet does not make the entire Solana runtime quantum-safe. It creates a wallet-specific authorization path where the spend proof is a one-time Winternitz signature checked against a root stored by the program.

Two formats in the code

The browser code currently supports two WOTS formats:

Format	Signature bytes	Source	Status
Legacy browser WOTS	512	`src/services/quantum/wots.ts`	Supported for backwards compatibility.
Solana Winternitz	896	`src/services/quantum/wots.ts`, `src/sdk/instructions.ts`, `crates/vaulkyrie-sdk/src/instruction.rs`, `programs/vaulkyrie-core/src/instruction.rs`	Current on-chain-compatible format.

The current Solana format uses:

32 chains
28-byte chain elements
256 chain steps
Keccak-derived chain hashing
896-byte signatures

Spend flow

Each spend consumes the current one-time signing key and advances the wallet to a next root.

Source map

Concern	Source
Key generation, derivation, signing, verification	`src/services/quantum/wots.ts`
Encrypted PQC key storage and migration	`src/services/quantum/quantumVaultStorage.ts`
Background signing session	`src/background/quantumVaultSession.ts`
UI	`src/pages/QuantumVault.tsx`
TS instruction builder	`src/sdk/instructions.ts`
Rust instruction builder	`crates/vaulkyrie-sdk/src/instruction.rs`
Shared protocol constants	`crates/vaulkyrie-protocol/src/lib.rs`
Program verification and state update	`programs/vaulkyrie-core/src/processor.rs`

Example: derive a phrase-backed PQC key

import {
  deriveSolanaWinternitzKeyPairFromMnemonic,
  generatePqcMnemonic,
} from "@/services/quantum/wots";

const mnemonic = generatePqcMnemonic();
const keyPair = await deriveSolanaWinternitzKeyPairFromMnemonic(mnemonic, {
  wallet: 0,
  parent: 0,
  child: 0,
});

Example: build the on-chain advance message

import { PublicKey } from "@solana/web3.js";
import { pqcWalletAdvanceMessage } from "@/services/quantum/wots";

const message = await pqcWalletAdvanceMessage(
  walletId,
  currentRoot,
  nextRoot,
  new PublicKey(destinationAddress).toBytes(),
  BigInt(amountLamports),
  BigInt(sequence),
);

Example: build an advance instruction

import { PublicKey } from "@solana/web3.js";
import { createAdvancePqcWalletInstruction } from "@/sdk";

const ix = createAdvancePqcWalletInstruction(
  new PublicKey(pqcWalletPda),
  new PublicKey(destinationAddress),
  {
    signature,
    nextRoot,
    amount: BigInt(amountLamports),
  },
);

Operational warning

Winternitz keys are one-time keys. Do not sign multiple messages with the same current key. In Vaulkyrie, a successful PQC spend must move from currentRoot to nextRoot.

Start Here

Architecture

Wallet Modes

Protocol Deep Dives

Developer Reference

What it protects against

Two formats in the code

Spend flow

Source map

Example: derive a phrase-backed PQC key

Example: build the on-chain advance message

Example: build an advance instruction

Operational warning

​What it protects against

​Two formats in the code

​Spend flow

​Source map

​Example: derive a phrase-backed PQC key

​Example: build the on-chain advance message

​Example: build an advance instruction

​Operational warning

What it protects against

Two formats in the code

Spend flow

Source map

Example: derive a phrase-backed PQC key

Example: build the on-chain advance message

Example: build an advance instruction

Operational warning