Shamir backup, or SLIP39, is a solid security standard that tackles the two biggest risks when it comes to safeguarding your wallet backup (recovery seed): theft and loss.
Understanding about Shamir backup
Your wallet backup is crucial for your digital assets. If you lose it, you could lose access to your crypto for good. To prevent this kind of disaster, It allows you to generate several unique recovery shares for backing up your private keys, with a specific number (known as the threshold) required to restore your wallet.
The Example
In a 2-of-3 Shamir backup setup, you generate three distinct shares, and any two of them can be used together to restore your wallet. If you happen to lose or have one share stolen, your wallet stays secure and can still be accessed with the other shares.
It involves several important steps:
- Generate: Figure out how many shares you want and how many are necessary for recovery.
- Distribute: Distribute them to reliable friends and/or safe places.
- Relax: Feel at ease knowing your private keys are protected, safe from being stolen or damaged.
This security protocol relies on a cryptographic algorithm developed by Adi Shamir, which is referred to as Shamir’s Secret Sharing.
Single backup vs Shamir backup
The table below gives a quick summary of the main differences between single and Shamir backup methods:
Title Page Separator Site title
| Feature | Single seed (BIP39) | Shamir backup (SLIP39) |
|---|---|---|
| Word length | 12, 18, or 24 words | 20 or 33 words |
| Number of shares | 1 (single seed) | 1 to 16 (multiple shares) |
| Word list | BIP-39 word list | Specific Shamir word list |
| Threshold for recovery | All words required (1/1) | User-specified (e.g., 2/3, 3/5) |
| Distribution flexibility | None (single copy) | Can distribute among trusted parties or locations |
| Redundancy | None | Configurable (e.g., 2/3 allows 1 backup) |
| Susceptibility to loss/theft | Complete loss if seed is lost/stolen | Loss tolerable up to threshold |