'Saves the public key in PKCS#1 DER format.
@returns: the DER-encoded public key.'

def _save_pkcs1_der(self):

    from pyasn1.codec.der import encoder
    from rsa.asn1 import AsnPubKey
    asn_key = AsnPubKey()
    asn_key.setComponentByName('modulus', self.n)
    asn_key.setComponentByName('publicExponent', self.e)
    return encoder.encode(asn_key)
