public UserAuthenticationDigest Hash(string password, byte[] salt)
        {
            var digest = new UserAuthenticationDigest();

            digest.Salt = salt;
            digest.Hash = this.HashWithSalt(password, digest.Salt);
            return(digest);
        }
        public bool IsValid(UserAuthenticationDigest digest, string password)
        {
            var newDigest = Hash(password, digest.Salt);

            return(newDigest.HashBase64.Equals(digest.HashBase64));
        }