METHOD FOR VERIFYING THE EXPECTED POSTAGE SECURITY DEVICE AND ITS STATUS

摘要

A secure and reliable method for verifying in the host system that the expected PSD is coupled to the host system includes generating a random numb er in the host system and encrypting the random number with a PSD state identification number. The encrypted random number is then sent to the PSD. The PSD decrypt s the encrypted random number received using the PSD state identification numb er and sends the decrypted random number to the host system. The host system compares the decrypted random number received from the PSO to the random number generated in the host system. If they are the same, the host system h as verified the expected PSD and has also verified that the PSD has not complet ed any transactions apart from the host system. A method for verifying that the expected host is coupled to the PSD mirrors the method for verifying the expected PSD .