Cross-domain file gateway
Secure file transfer between isolated networks

PSTfile is an automatic file transfer system that allows moving or copying files between two separated TCP/IP networks. PSTfile enables information flow control and real time monitoring of file transfers.

PSTfile is one of the products of the PSTgateways family. All PSTgateways products share the same architecture which provides common administration and security infrastructure. Individual products differ in the supported data flows, called services.


PSTfile guarantees the impossibility of any type of traffic between the two networks except the files transferred by the system itself.

The gateway does not substitute the file servers on the two networks but rather uses them as intermediary elements for sending and receiving the files. The system is exclusively administered from the secure network.

The gateway always plays the client role of the supported protocols. Both services work automatically once source and target have been configured. Their main difference is that outbound files must be digitally signed in order to be transferred by the system.

Inbound File Transfers

Inbound file transfer works automatically: the gateway periodically checks the external network folders which have configured, enters the files it finds into the internal network and uploads them to the configured destination folders on the internal network.

Files enter an isolated network in a transparent way for the users. Filtering policies, based on size and name can be applied.

Inbound File Channel
This is the name given to the correspondence between a folder on an external network file server and a folder on an internal network file server. There are also a number of parameters that can be individually specified for each channel, such as priority and mirror or recursive mode.

Outbound File Transfers

It works in a similar way as the inbound file service, with the source folder being on the isolated network and destination folder on the external network. The big difference is that a digital signature is required for the files to be transferred.

Main Benefits


  • Common Criteria Certified at EAL 2+
  • Inbound and outbound flows work independently
  • Outbound file transfers require authorization using a digital signature for each file
  • The one-way version of PSTfile can advantageously replace a manual air gap or data diode


  • Real-time file transfers
  • Transparent to the isolated network users
  • Easy to deploy – Nothing to install on servers

Technical data

  • Handles up to 250 channels
  • Supports Internet protocols: FTP, FTPS, SMB
  • Transfer rate: 130 Mbps
  • Maximum file size: 20 GB