The two most common ways to lose cryptocurrency are having your key stolen and losing it. Qanum's consensus rules include one tool for each. They do not depend on a particular wallet or on any intermediary: every node on the network enforces them.
If your key is stolen: vaults
A vault has two keys:
- an everyday key (ML-DSA-87), the one you spend with;
- a cold key, kept offline.
Every spend with the everyday key goes through a waiting window that you choose when you create the vault, for example 1,152 blocks (about one day). During the window the spend is visible on the network, and the cold key can cancel it instantly and move the coins somewhere safe.
If someone steals your everyday key, they cannot take the coins straight away: the theft is in plain sight and you have the whole window to undo it.
What consensus guarantees:
- The everyday key has no shortcut: it can only start the window; there is no way to spend around it.
- The window is fixed by the vault, not by whoever starts the spend: a thief cannot shorten it.
- Cancelling does not require knowing where the money was going: seeing that the window started is enough.
- The two keys must differ; a single-key vault is invalid.
- Window: from 144 blocks (about 3 hours) to 5,256,000 blocks (about 12.5 years).
Extra post-quantum protection. If the cold key is SLH-DSA (hash-based signatures), it belongs to a different cryptographic family from the everyday key (ML-DSA, lattice-based). Breaking a single signature type is not enough to empty the vault.
If you lose your key: delayed recovery
A coin can have a main key (ML-DSA-87) and a recovery key (SLH-DSA) that you keep separately. The main key spends at any time. The recovery key can only move the coin once the number of blocks you chose has passed since you received it: from 144 blocks (about 3 hours) to about 12.5 years.
If you ever lose the main key, the recovery key gives you access back once the delay has passed.
Note: recovery protects against loss, not theft. Whoever holds your main key can still spend. Against theft, use a vault.
What they do not solve
- If your cold key is stolen, or both keys are, there is no protection: keep it offline.
- The network must be watched during the window. If nobody cancels in time, the final spend confirms and is irreversible.
- Choose a window with margin: your real reaction time is the window minus the time it takes you to notice and to get the cancellation confirmed.
- They do not protect against physical coercion.
Learn more
- Vault adversarial analysis: every spend route, who can cancel and the limits.
- Whitepaper, section 14: vaults and recovery in the design.
- Post-quantum signatures: ML-DSA and SLH-DSA compared.
- FAQ: short answers about Qanum.