COLDCARD vulnerability what happened, and what to do
Informational only, and this site never asks for your recovery words. details

Informational only. This is independent analysis and an evidence-backed explainer, not financial, security or legal advice, and not a substitute for professional advice about your own situation. It is not affiliated with, endorsed by, or speaking for Coinkite, Block, or any other party named here. Published estimates are attributed, and differing scenarios are kept separate with their assumptions. Act on your own judgement. Editorial standards and corrections.

Do not disclose recovery material to a website, form, message or support account. This site never asks for it. Deliberate recovery on independently verified offline equipment is a separate operation. Seed-word safety.

Initial attack-cost model

llfourn-model

https://x.com/LLFOURN/status/2082990000896147942

Author
@LLFOURN
Organisation
independent
Evidence role
social statement
Posted
31 Jul 2026, 00:41 UTC
Capture status
capture held
Artefacts held
4

LLFOURN's stated attack-cost model: approximately 2^40.3 for Mk3 and 2^72.3 for Mk4-class devices under its listed UID, timing and interaction assumptions.

This post is registered as evidence and has locally held capture artefacts. The original remains the canonical publication; hashes below identify the files held by this project.

How to check this yourself

The SHA-256 prefixes above identify each held copy without turning this page into a mirror of somebody else's post. Compare a quotation against the original. If the post has since been edited or deleted, ask and the held copy can be produced.