def test_depseudonymize(self):
    ip = os.urandom(16)

    # manually compute investigator-local pseudonym
    pseudonym_secrets = {}
    for peer_secrets in self.secrets.peers.values():
        for shard, shard_secrets in peer_secrets.by_shard.items():
            pseudonym_secrets[shard] \
                = shard_secrets.pseudonym_component_secret

    s = 1
    e = ed25519.scalar_unpack(common.sha256(b"PEP3 investigator"))
    for secret in pseudonym_secrets.values():
        s *= pow(ed25519.scalar_unpack(secret), e, ed25519.l)
        s %= ed25519.l

    investigator_local_ip = (ed25519.Point.lizard(ip) * s).pack()

    # manually create warrant
    warrant = pep3_pb2.DepseudonymizationRequest.Warrant()
    warrant.act.actor = b"PEP3 investigator"
    warrant.act.name.state = pep3_pb2.Pseudonymizable.UNENCRYPTED_PSEUDONYM
    warrant.act.name.data = investigator_local_ip

    self.investigator.encrypt([warrant.act.name],
                              self.investigator.public_keys['pseudonym'])

    warrant.signature = crypto.sign(
        crypto.load_privatekey(crypto.FILETYPE_PEM,
                               self.secrets.root_certificate_keys.warrants),
        warrant.act.SerializeToString(), 'sha256')

    result = self.investigator.connect_to("investigator") \
        .Depseudonymize(warrant)

    self.assertEqual(result.data, ip)