Function split

pub fn split(
    secret_share: &SecretShare,
    identity_provider: &impl IdentityProvider,
) -> Result<(SigningShare, SubShare), Error>

Given a “secret share” and an identity provider, returns “signing share” and “sub-share” that can be used to reconstruct the “secret share” given the same identity provider.

Ref: https://wamu.tech/specification#share-splitting.