Stacks Labs Moves sBTC on Mainnet With Lamport Signatures
Stacks Labs moved 0.00001 sBTC through a hash-based Lamport signature verifier on Stacks mainnet on Oct. 15. It is an opt-in vault path, not a quantum upgrade for existing sBTC or the Taproot-held Bitcoin backing it.
0.00001 sBTC. That is how much Stacks Labs pushed through a hash-based signature verifier on Stacks mainnet on Oct. 15. The announcement came Nov. 11, when Stacks called it the "first post-quantum sBTC transfer on Stacks mainnet."
The amount is tiny. The test is the point.
The mainnet transaction called the pq-vault contract's sBTC withdrawal function and selected its lamport verifier. That verifier implements Lamport one-time signatures built on SHA-256 hashes. Each key may sign only one message digest.
How the vault works
A withdrawal signature binds the amount, the recipient and the next key, among other details. Anyone can submit a signed withdrawal. Funds still go only to the recipient the signature authorizes.
Every successful withdrawal installs the next key, so the vault rotates keys with each spend.
What it does not do
This is not a quantum-security upgrade for existing sBTC balances or the Bitcoin backing them. It shows one way to authorize withdrawals from a dedicated vault, and users would have to opt in.
Stacks documentation describes sBTC's Bitcoin backing as held in a Taproot address controlled by a threshold of signers. The vault's hash-based authorization does not replace that mechanism or remove its quantum exposure. The peg also runs on a permissioned signer set that started with 15 institutional operators.
The "first" claim has limits
The claim is specific to sBTC on Stacks. StarkWare announced a quantum-safe Bitcoin mainnet transaction demonstration on Aug. 26, and that one ran on Bitcoin itself.
Context
Stacks' 2030 roadmap lists post-quantum security as one of three core goals, alongside Bitcoin capital markets and institutional privacy. As of early November 2026, public descriptions still placed the work at the research stage. Stacks Labs' upgrade vision through 2030 calls for adopting new signature schemes through network governance.
Scale is the open question. sBTC supply hit roughly 2,487 BTC by the end of Q3 2026. Deposits opened Dec. 17, 2024; withdrawals followed from April 30, 2025.
One transfer is a proof of concept. Scaling it and opening it to ordinary users remain unresolved, and any quantum-resistant layer still settles to a base chain running today's cryptography.
The institutional side of that roadmap has drawn backers before, as when Fireblocks backed Stacks as an institutional gateway.
