public override bool MatchesKeyIdentifierClause(SecurityKeyIdentifierClause keyIdentifierClause)
        {
            LocalIdKeyIdentifierClause lkic = keyIdentifierClause as LocalIdKeyIdentifierClause;

            if (lkic != null && lkic.LocalId == Id)
            {
                return(true);
            }

            InternalEncryptedKeyIdentifierClause khic = keyIdentifierClause as InternalEncryptedKeyIdentifierClause;

            if (keyhash == null)
            {
                keyhash = SHA1.Create().ComputeHash(wrapped_key);
            }
            if (khic != null && khic.Matches(keyhash))
            {
                return(true);
            }

            return(false);
        }