Back to: Security & Self-Custody Advanced
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Objective: build a 2-of-3 multisig on testnet that survives losing any single key — the professional standard for serious holdings.
Concept refresher
2-of-3: three keys exist, any two authorize. Lose one → recover with the other two. One stolen → useless alone. Distribute across locations/people so no single event (theft, fire, coercion) reaches quorum.
Hands-on lab (testnet, free)
- Create three testnet keys (separate wallet instances or devices).
- Deploy a 2-of-3 safe (Safe{Wallet} testnet deployment or equivalent); record all three addresses.
- Fund with testnet dust; execute a transaction requiring two signatures from two different instances.
- Recovery drill: simulate losing key #3 (delete that instance) — prove keys #1+#2 still move funds.
- Document the setup: which key lives where, who knows what, recovery order.
Safety checklist
- Never store two keys in one place (defeats the entire purpose).
- All cosigners verify destination addresses independently before signing.
- Test recovery *before* funding with real amounts — drills, not hopes.
- Keep the setup document where heirs can find it (sealed, not emailed).
Related glossary
Next lesson: recovery without a seed — risks and realities.