Function cryptoballot::recover_secret_from_shares

pub fn recover_secret_from_shares(
    threshold: u8, 
    shares: Vec<Vec<u8>>
) -> Result<Vec<u8>, Error>

Given a set of secret shares recovered from all SecretShareTransaction, reconstruct the secret decryption key. The decryption key can then be used to decrypt votes and create a DecryptionTransaction.