Privacy and Security

Tomo Wallet uses privacy-preserving Multi-Party Computation (MPC) technology to protect user data by encrypting the seed phrase and storing it in a sharded manner across multiple points.

Shamir's Secret Sharing

Tomo wallet embraces Shamir's Secret Sharing(SSS), an MPC method that mathematically splits a secret (private key) into multiple shares.

Consider your 256-bit secret as an element in with . An SSS scheme samples random elements from to construct a polynomial of degree and as the constant term. SSS randomly picks a distinct value for each shareholder and computes the share as . Then, the secret owner can use shares to reconstruct the polynomial through a polynomial interpolation (e.g., Lagrange interpolation) and recover the secret as .

SSS is an elegant method and supports two critical features for key management:

1. SSS is statistically secure with security bits equal to the bit-length ( ) of your secret , which means access to shares brings no information to the attacker about the secret . This feature prevents the unauthorized parity from stealing the key by hacking the parties' device.

2. If there are intotal shares, even shares are lost unfortuantely, one can still recover the from the remaining shares. This feature provides a security redundancy for users to recover their key after a disaster loss.

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