Coinbase proposes quantum-resistant Bitcoin signatures that could increase signature data tenfold
Coinbase outlines a plan for quantum-safe Bitcoin addresses and signatures, including a draft scheme where stateless signatures reach 5,777 bytes.
Why it matters
If adopted, quantum-resistant signatures would significantly increase Bitcoin transaction sizes and require new address formats, affecting node operators, wallet developers, and custody providers. The timeline and specific standards remain undecided.
Key facts
Brian Armstrong called for industry preparation and collaboration on quantum-resistant Bitcoin on October 20
Reported by CryptoSlate
The SHRINCS draft signature scheme specifies a stateless signature size of 5,777 bytes
5,777 bytesReported by CryptoSlate
SHRINCS stateful signatures range from 548 to 4,619 bytes with a 48-byte public key
Reported by CryptoSlate
Coinbase established a quantum advisory board in January featuring Scott Aaronson, Dan Boneh, and Justin Drake
Reported by Bankless
Coinbase proposes separating address containers from signature methods to support future cryptographic changes
Reported by Bankless
BIP-360 (P2MR) and P2TRv2 are cited as potential quantum-resistant address designs
Reported by Bankless
What happened
Coinbase published a proposal for making Bitcoin resistant to quantum computing attacks. Brian Armstrong called for industry collaboration on October 20, building on an October 13 article by Shashank Agrawal. The draft SHRINCS signature scheme uses a 48-byte public key, stateful signatures of 548 to 4,619 bytes, and a stateless fallback of 5,777 bytes when signing state is unavailable. Coinbase began this effort in January with a quantum advisory board including Scott Aaronson, Dan Boneh, and Justin Drake, and in July joined BlackRock, Fidelity, and Strategy in the Bitcoin Security Consortium pledging $15 million over three years. The proposal separates address containers from signature methods to allow future cryptographic upgrades, citing BIP-360 (P2MR) and P2TRv2 as potential address designs.
How the story developed
- Official statement
Shashank Agrawal publishes Coinbase article on quantum-safe signatures
Outlines requirements for signature schemes compatible with wallets, recovery, and custody servers
- Official statement
Brian Armstrong calls for industry collaboration on quantum preparation
Renews attention to recovery and signing-server requirements from Agrawal's article
- First report
First report by CryptoSlate
Quantum-proof Bitcoin signatures would clog network nodes with 10x larger data
- Update
CryptoSlate reports on SHRINCS signature size implications
Stateless fallback signatures of 5,777 bytes could increase signature data tenfold
- Independent corroboration
Independently corroborated by Bankless
Coinbase's Plan for a Quantum-Safe Bitcoin
- Update
Coinbase establishes quantum advisory board
Board includes researchers Scott Aaronson, Dan Boneh, and Justin Drake
- Official statement
Bitcoin Security Consortium launches with $15M pledge
Coinbase joins BlackRock, Fidelity, and Strategy in three-year security research commitment
- Update
Bankless publishes detailed analysis of Coinbase quantum-safe Bitcoin plan
Covers address-container separation, BIP-360, P2TRv2, and migration strategy for existing coins
How coverage built up
Independent sources over time, counted the way the consensus panel counts them: a republication of a wire story does not move the line.
- 21 Oct 2026, 08:30 UTC: CryptoSlate — 1 independent source, 1 reports
- 21 Oct 2026, 17:24 UTC: Bankless — 2 independent sources, 2 reports
Affected entities
Original sources
| Publisher | Report | Role | Published |
|---|---|---|---|
| CryptoSlate Crypto media | Quantum-proof Bitcoin signatures would clog network nodes with 10x larger data | Original | |
| Bankless Crypto media | Coinbase's Plan for a Quantum-Safe Bitcoin | Independent |
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