New wallet offers way to tackle Bitcoin’s quantum risk without a fork

Developers behind a new wallet product say they have found a way to tackle quantum computing risks using a smart contract layer that runs alongside Bitcoin without requiring any change to the network itself.

Postquant Labs unveiled Quip Network’s post-quantum bitcoin wallet Tuesday, the company told CoinDesk in an email. The product runs on Arch Network, a system that lets developers build smart contracts anchored directly to Bitcoin rather than on a separate chain or through wrapped tokens.

Quip uses that infrastructure to add a post-quantum signature scheme called WOTS+, short for Winternitz One-Time Signature, on top of Bitcoin’s existing security. WOTS+ is a tested cryptographic technique that does not rely on the elliptic curve math a quantum computer could break.

By using a “Layer 2” — shorthand for a separate network built on top of Bitcoin that processes transactions and settles back to the main chain—developers can add features without changing Bitcoin’s base layer.

“The Bitcoin community has delayed a fix for years, despite Satoshi himself discussing the quantum problem,” Postquant Labs CEO Colton Dillion said in a statement to CoinDesk. “Developers say any protocol upgrade could take 5 to 10 years, but with Quip’s approach, we provide similar protection immediately.”

Bitcoin’s quantum readiness

The launch arrives in the middle of an active fight over how Bitcoin should respond to quantum risk.

Prominent developer Jameson Lopp and five others proposed BIP-361 two weeks ago, which would phase out quantum-vulnerable addresses on a fixed five-year timeline and freeze coins that fail to migrate, including the roughly 1.1 million bitcoin attributed to pseudonymous creator Satoshi Nakamoto.

Paul Sztorc’s controversial eCash hard fork would copy Bitcoin’s chain and ship seven sidechains including a quantum-resistant one, funded partly by reassigning Satoshi-pattern coins on the new ledger to investors.

Both proposals have drawn pushback from the community.

Quip’s pitch is that neither approach is necessary. The setup requires no soft fork, no consensus change, no community vote. A soft fork is a Bitcoin upgrade that tightens existing rules so older software still works, but it still needs broad miner and node support to activate. Bitcoin’s last major soft fork was Taproot in 2021. The next one, if it happens, could take years.

Technical trade-offs

The three approaches actually disagree on something specific. Lopp’s argument is that Layer 2 protection like Quip’s is insufficient because Bitcoin mainnet public keys still leak the moment a user broadcasts a transaction, giving a future quantum attacker a target.

There are a few caveats, however. The wallet app launches next week rather than today. A third-party audit is underway but not complete. Quip’s quantum-resistant accounts already exist on Ethereum and Solana, but the Bitcoin deployment is new and Arch Network is still relatively early infrastructure.

Postquant Labs CTO Dr. Richard Carback, a long-time collaborator with eCash inventor Dr. David Chaum who now advises the project, said the approach narrows the window for a quantum attack to as little as two blocks, roughly 20 minutes.

(David Chaum’s eCash is the original digital cash protocol from 1983, the academic foundation for ‘blind’ signatures and privacy-preserving electronic money. It predates Bitcoin by 25 years and has nothing to do with Bitcoin or the eCash proposal by Sztorc.)

Sztorc’s argument is that incremental patches are exactly why Bitcoin needs a clean fork with quantum resistance built in from the start. The Layer 2 approach, which now includes Quip and Blockstream’s hash-based signature work on the Liquid Network, argues both other positions overreact to a threat that better infrastructure can handle without changing Bitcoin itself.

Which approach wins depends partly on how fast quantum computers actually arrive. The Bitcoin holders most worried about quantum risk have historically been the same group most resistant to wrapped or smart-contract-anchored products.