Struct Scheme 

pub struct Scheme { /* private fields */ }

The main struct implementing Shamir’s Secret Sharing scheme

Implementations

impl Scheme

pub fn new( threshold: usize, total_shares: usize, prime_modulus: BigUint, ) -> Result<Self, SssError>

Creates a new Shamir’s Secret Sharing scheme with the specified parameters.

Arguments

• threshold - Minimum number of shares needed to reconstruct the secret (k)
• total_shares - Total number of shares to generate (n)
• prime_modulus - Prime number defining the finite field. Must be larger than both the secret and total_shares.

Returns

• Ok(Scheme) - If parameters are valid
• Err(SssError::InvalidThreshold) - If threshold is 0 or greater than total_shares

Example

use num_bigint::BigUint;
use shamir_rs::Scheme;
 
let prime = BigUint::from(257u32);
let scheme = Scheme::new(3, 5, prime).unwrap();

pub fn split_secret(&self, secret: &BigUint) -> Vec<Share>

Splits a secret into n shares where k shares are required to reconstruct.

Arguments

• secret - The secret to split. Must be less than prime_modulus.

Returns

A vector of n shares. Each share is a point on a random polynomial of degree k-1 where the constant term is the secret.

Example

let secret = BigUint::from(123u32);
let shares = scheme.split_secret(&secret);
assert_eq!(shares.len(), 5);

pub fn reconstruct_secret(&self, shares: &[Share]) -> Result<BigUint, SssError>

Reconstructs a secret from k or more shares using Lagrange interpolation.

Arguments

• shares - Slice of shares to use for reconstruction. Must contain at least k shares with unique indices.

Returns

• Ok(BigUint) - The reconstructed secret
• Err(SssError::NotEnoughShares) - If fewer than k shares provided
• Err(SssError::DuplicateShares) - If shares contain duplicate indices

Example

let reconstructed = scheme.reconstruct_secret(&shares[0..3]).unwrap();
assert_eq!(reconstructed, secret);

Trait Implementations

impl Debug for Scheme

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.