UK research organisation · London
Quantum computing and the security of cryptocurrency.
Wildcross is an independent UK research organisation. We measure how exposed cryptocurrency and digital asset infrastructure are to quantum attack, test post-quantum replacements, and turn the results into evidence for UK government, regulators and regulated firms.
- Focus
- Quantum threat to digital assets
- Research workstreams
- 4
- Programme length
- 36 months
- Based in
- United Kingdom
01 · The problem
The signatures that secure cryptocurrency will not survive a large quantum computer.
Bitcoin, Ethereum and most other public blockchains authorise transactions with elliptic-curve signatures. Shor's algorithm, run on a large fault-tolerant quantum computer, can recover a private key from its public key. Any coin whose public key is visible on-chain could then be taken.
Estimates of the hardware needed for this fell sharply in 2026. Over the same period the UK set firm dates for moving to post-quantum cryptography and finalised rules bringing cryptoasset firms under FCA regulation.
<500,000 qubits
Physical qubits Google Quantum AI estimates are needed to break secp256k1, the curve used by Bitcoin and Ethereum, on superconducting hardware.
~9 minutes
The same paper's average time to solve for a key on a first-generation fast-clock machine, shorter than Bitcoin's typical 10-minute block interval.
~10,000 qubits
Physical qubits a Caltech and Oratomic team estimate could be enough on reconfigurable neutral-atom hardware, with run times measured in days rather than minutes.
~6.7M BTC
Held in addresses the Google paper considers quantum-vulnerable, including about 1.7M BTC in early pay-to-public-key outputs.
Bitcoin in quantum-vulnerable addresses
Pay-to-public-key outputs
Other vulnerable addresses, including reused keys
Rest of supply (about 20M in total)
What Wildcross adds
Most published work on this question comes from hardware companies and US research groups, and it stops at the size of the threat. Wildcross is independent of any quantum hardware vendor or cryptoasset business, and it takes the next step: connecting those estimates to the obligations UK-regulated firms now face under NCSC guidance and the FCA regime.
| Output type | Public key on-chain | Status | Notes |
|---|---|---|---|
| P2PK | Always | Exposed at rest | Used for many 2009–2010 coins; many keys believed lost |
| P2PKH / P2WPKH, reused | After first spend | Exposed at rest | Remaining balance is exposed once the address has spent |
| P2TR (Taproot) | Always (tweaked key) | Exposed at rest | Key-path spending reveals a usable public key |
| P2PKH / P2WPKH, unused | Only when spending | Exposed in transit | Risk sits in the window between broadcast and confirmation |
| P2MR (BIP-360) | No key path | Designed to resist | Proposed; merged into the BIP repository February 2026, not activated |
BIP-360 status reported by Bitcoin Magazine, February 2026
02 · Research programme
Four workstreams over three years.
Each workstream has a defined research question, a method that can be checked by others, and outputs that will be published openly.
WS1
Quantum resource estimates for blockchain cryptography
How many qubits, and how much time, would it take to break the curves used by major blockchains (secp256k1, Ed25519, BLS12-381) on each leading hardware platform? We will produce independent UK estimates and update them as hardware roadmaps change.
WS2
Measuring on-chain exposure
How much value on Bitcoin, Ethereum and other major chains sits behind public keys that are already visible, and how is that changing? We will build a repeatable census by output type, age and holder category.
WS3
Post-quantum signatures on distributed ledgers
What do the NIST post-quantum signature standards cost when used on a blockchain? We will benchmark ML-DSA, SLH-DSA and hash-based schemes for signature size, verification time and fees, and test hybrid designs and proposals such as BIP-360.
WS4
Migration and policy for UK-regulated firms
How should UK exchanges and custodians plan their move to post-quantum cryptography against the NCSC milestones and the FCA regime? We will turn the findings from WS1 to WS3 into evidence for policymakers and practical guidance for firms.
Workstream
Year 1
Year 2
Year 3
WS1 Resource estimates
Baseline estimates
Platform comparison
Updated report
WS2 On-chain exposure
Bitcoin census
Ethereum and others
Live index
WS3 PQ signatures
Benchmarks
Hybrid designs
WS4 Migration and policy
Landscape briefing
UK framework
Work is phased so that WS3 begins once the WS1 baseline is complete. Parts of WS1 and WS3 are intended to be delivered with university partners.
03 · UK priorities
Why this work matters to the UK.
The programme is designed to support existing UK commitments on quantum technology, cyber security and financial regulation.
NCSC
The NCSC expects organisations to finish discovery and planning by 2028, migrate their most critical systems by 2031, and complete migration to post-quantum cryptography by 2035. Digital asset firms need evidence specific to blockchains to meet these dates.
FCA
The UK cryptoasset regime is expected to come into force on 25 October 2027, and firms can already apply for authorisation. Newly regulated firms will need to show they understand long-term cryptographic risk.
DSIT
On 17 March 2026 the government announced up to £2 billion to roll out quantum computing at scale, naming financial services as an application area and national security as a goal. Understanding what these machines will be able to break is part of deploying them safely.
International standards
NIST's transition guidance deprecates elliptic-curve and RSA signatures after 2030 and disallows them after 2035, with ML-DSA and SLH-DSA as replacements.
04 · Who uses this work
Research built to be used.
Government and regulators
Independent evidence on timescales and exposure to inform policy, supervision and guidance for the digital asset sector.
UK-regulated firms
Exchanges and custodians planning their migration against NCSC milestones, using our framework and benchmarks.
Protocol developers
Benchmark data on post-quantum signature schemes to inform upgrade proposals on major blockchains.
Researchers and standards bodies
Open methods, estimators and aggregated datasets that others can test, reproduce and extend.
Beyond the funded programme, Wildcross will sustain the work through research partnerships and commissioned analysis for public bodies and regulated firms, while keeping core outputs open.
05 · How we work
Research principles.
Open by default
Reports, aggregated datasets and benchmark code are published under open licences so others can check and build on them.
Responsible disclosure
Findings that could help an attacker are shared first with the NCSC and the relevant protocol maintainers before publication. We do not publish attack tools.
Careful with data
Exposure data is published in aggregate only. We do not publish lists of individual addresses or attempt to identify their owners.
Independent
We do not hold, trade or promote cryptoassets, and we do not give investment advice.
Confidential where it must be
Some work with partners is carried out under confidentiality and shared only with authorised parties.
UK-based delivery
Research is carried out in the UK, with personal data handled in line with UK GDPR.
06 · Team
Research roles.
Director
Programme leadership and partnerships
Lead, Cryptography
Post-quantum signatures (WS3)
Lead, Quantum Algorithms
Resource estimates (WS1)
Lead, Data and Protocols
On-chain exposure (WS2)
We are developing partnerships with UK universities and research centres for each workstream. Academic groups interested in collaborating are welcome to get in touch.
07 · Partners
Partner access.
Some of our research is shared only with government, regulatory and research partners. Authorised partners can sign in to view:
- Research findings and briefings not yet in the public domain
- Details of current research and institutional partners
- Working papers and data shared under confidentiality
Access by invitation
Access is granted by Wildcross. Public-sector and research organisations can request access using the contact form.
08 · Contact
Get in touch.
For government and public-sector enquiries, research partnerships, partner access or press.
Emailhello@wildcross.co.uk
LocationLondon, United Kingdom