Secure one-way data transfer using communication interface circuitry

A method of transferring data from a Send Node to a Receive Node over an optical data link, comprising the steps of:

• providing a first and a second network interface circuitry;
• configuring said first network interface circuitry to enable data transfer from said Send Node to said optical data link, but to disable any data transfer from said optical data link to said Send Node;
• configuring said second network interface circuitry to enable data transfer from said optical data link to said Receive Node, but to disable any data transfer from said Receive Node to said optical data link;
• coupling said configured first network interface circuitry to said Send Node and a first end of said optical data link;
• coupling said configured second network interface circuitry to said Receive Node and a second end of said optical data link;
• and
• transferring data from said Send Node to said Receive Node over said optical data link,
• wherein said first network interface circuitry and said second network interface circuitry are separately administered and require independent authentication keys for communication management;
• said step of configuring said first network interface circuitry comprises the steps of:
• populating a first optical emitter and a first optical detector on a first network interface card;
• configuring said first optical emitter to enable data transfer from said Send Node to said optical data link;
• configuring said first optical detector to disable any data transfer from said optical data link to said Send Node;
• leaving a space on said first network interface card for a second optical emitter and a second optical detector unpopulated;
• and
• said step of configuring said second network interface circuitry comprises the steps of:
• populating a third optical emitter and a third optical detector on a second network interface card;
• configuring said third optical emitter to disable any data transfer from said Receive Node to said optical data link;
• configuring said third optical detector to enable data transfer from said optical data link to said Receive Node;
• leaving a space on said second network interface card for a fourth optical emitter and a fourth optical detector unpopulated.