def encrypt(self, key, iv="", cek="", **kwargs):
        """
        Produces a JWE as defined in RFC7516 using RSA algorithms

        :param key: RSA key
        :param iv: Initialization vector
        :param cek: Content master key
        :param kwargs: Extra keyword arguments
        :return: A signed payload
        """

        _msg = as_bytes(self.msg)
        if "zip" in self:
            if self["zip"] == "DEF":
                _msg = zlib.compress(_msg)
            else:
                raise ParameterError("Zip has unknown value: %s" % self["zip"])

        kwarg_cek = cek or None

        _enc = self["enc"]
        iv = self._generate_iv(_enc, iv)
        cek = self._generate_key(_enc, cek)
        self["cek"] = cek

        logger.debug("cek: %s, iv: %s" % ([c for c in cek], [c for c in iv]))

        _encrypt = RSAEncrypter(self.with_digest).encrypt

        _alg = self["alg"]
        if kwarg_cek:
            jwe_enc_key = ''
        elif _alg == "RSA-OAEP":
            jwe_enc_key = _encrypt(cek, key, 'pkcs1_oaep_padding')
        elif _alg == "RSA-OAEP-256":
            jwe_enc_key = _encrypt(cek, key, 'pkcs1_oaep_256_padding')
        elif _alg == "RSA1_5":
            jwe_enc_key = _encrypt(cek, key)
        else:
            raise NotSupportedAlgorithm(_alg)

        jwe = JWEnc(**self.headers())

        try:
            _auth_data = kwargs['auth_data']
        except KeyError:
            _auth_data = jwe.b64_encode_header()

        ctxt, tag, key = self.enc_setup(_enc, _msg, key=cek, iv=iv,
                                        auth_data=_auth_data)
        return jwe.pack(parts=[jwe_enc_key, iv, ctxt, tag])
Produces a JWE as defined in RFC7516 using RSA algorithms

        :param key: RSA key
        :param iv: Initialization vector
        :param cek: Content master key
        :param kwargs: Extra keyword arguments
        :return: A signed payload