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 on Tuesday, the company told CoinDesk in an email. The product runs on the Arch Network, a system that lets developers build smart contracts anchored directly to Bitcoin instead of on a separate chain or through wrapped tokens.
Quip uses this 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 mathematics that a quantum computer could break.
By using a “Layer 2” — short for a separate network built on top of Bitcoin that processes transactions and feeds back to the main chain — developers can add features without changing Bitcoin’s base layer.
“The Bitcoin community has delayed a solution 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 can take 5 to 10 years, but with Quip’s approach, we provide similar protection immediately.”
Bitcoin’s Quantum Contingency
The launch arrives amid an active battle 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 cannot 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 send seven sidechains, including a quantum-resistant one, funded in part by redistributing Satoshi pattern coins on the new ledger to investors.
Both proposals have withdrawn from the community.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 that 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 considerations
The three approaches actually disagree on something specific. Lopp’s argument is that Layer 2 protection like Quips is insufficient because public Bitcoin mainnet keys still leak the moment a user issues a transaction, giving a future quantum attacker a target.
However, there are a few caveats. The Wallet app will launch next week rather than today. A third party audit is ongoing but not completed. Quip’s quantum-resistant accounts already exist on Ethereum and Solana, but the Bitcoin implementation is new and the Arch Network is still relatively early infrastructure.
Postquant Labs CTO Dr. Richard Carback, a longtime collaborator with eCash inventor Dr. David Chaum, who is now advising the project, said the approach narrows the window for a quantum attack to as little as two blocks, about 20 minutes.
(David Chaum’s eCash is the original 1983 digital money protocol, the academic basis 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 of Sztorc.)
Sztorc’s argument is that incremental patches are exactly why Bitcoin needs a clean fork with built-in quantum resistance from the start. The Layer 2 approach, which now includes Quip and Blockstream’s hash-based signature work on the Liquid Network, argues that both other positions are overreacting to a threat that better infrastructure can handle without changing Bitcoin itself.
Which approach wins depends in part on how quickly quantum computers actually arrive. The Bitcoin holders most concerned about quantum risk have historically been the same group most resistant to packaged or smart-contract-anchored products.
