Developers behind a new wallet product say they have found a way to combat the risks of quantum computing by using a smart contract layer that runs alongside Bitcoin without requiring any changes to the network itself.
Postquant Labs revealed Quip Network’s post-quantum bitcoin wallet on Tuesday, the company told CoinDesk in an email. The product runs on Arch Network, a system that allows developers to create smart contracts directly anchored in Bitcoin rather than on a separate chain or via wrapped tokens.
Quip uses this infrastructure to add a post-quantum signature system 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 elliptic curve calculations that a quantum computer could break.
By using a “layer 2” – shorthand for a separate network built on top of Bitcoin that processes transactions and returns to the main chain – developers can add functionality without changing Bitcoin’s base layer.
“The Bitcoin community has delayed a solution for years, although Satoshi himself has discussed the quantum problem,” Colton Dillion, CEO of Postquant Labs, said in a statement to CoinDesk. “The developers say any protocol upgrade could take 5-10 years, but with Quip’s approach, we provide similar protection immediately.”
The quantum preparation of Bitcoin
The launch comes amid an active struggle 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 vulnerable quantum addresses over a fixed five-year schedule and freeze coins that fail to migrate, including the approximately 1.1 million bitcoins 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 in part by repurposing Satoshi model coins on the new ledger to investors.
Both proposals sparked resistance from the community.
Quip’s argument is that neither approach is necessary. The setup requires no soft forks, no consensus changes, no community votes. A soft fork is a Bitcoin upgrade that strengthens existing rules so that old software still works, but it still requires broad miner and node support to enable. The last major soft fork of Bitcoin was Taproot in 2021. The next one, if it happens, could take years.
Technical compromises
The three approaches actually disagree on something specific. Lopp’s argument is that Layer 2 protection like Quip’s is insufficient because the Bitcoin mainnet’s public keys always leak the moment a user broadcasts a transaction, giving a future quantum attacker a target.
There are some caveats, however. The wallet app will launch 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 Bitcoin’s deployment is new and Arch Network is still relatively early infrastructure.
Dr. Richard Carback, CTO of Postquant Labs and longtime collaborator of eCash inventor Dr. David Chaum, who is now advising the project, said the approach reduced the window for a quantum attack to just two blocks, or about 20 minutes.
(David Chaum’s eCash is the original digital currency protocol from 1983, 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 Sztorc’s eCash proposal.)
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 signing work on the Liquid network, argues that the other two positions are overreacting to a threat that better infrastructure can handle without modifying Bitcoin itself.
Which approach wins depends in part on how quickly quantum computers actually arrive. Bitcoin holders most worried about quantum risk have historically been the same group most resistant to products wrapped or anchored in smart contracts.
