Patent ID: 6986051

Claim:
A method for use in a virus-free certificate firewall in controlling and filtering files using a virus-free certificate, the method comprising the steps of: the firewall receiving a file; if a virus-free certificate is required for the file, searching through at least one cache of stored virus-free certificates to determine whether one of the stored virus-free certificates corresponds to the file; if a stored virus-free certificate is found which corresponds to the file, authenticating the corresponding stored virus-free certificate, said corresponding stored virus-free certificate comprising a certificate signature; if the corresponding stored virus-free certificate is authenticated, determining whether the file is virus-free or not; if the file is virus-free, forwarding the file with the corresponding stored virus-free certificate; if the corresponding stored virus-free certificate is not authenticated or if no corresponding stored virus-free certificate associated with the file is found, determining whether the file is virus-free; if the file is virus-free, associating with the file a new virus-free certificate, storing the new virus-free certificate, and forwarding the file with the new virus-free certificate.