Shrouded Gate

Shrouded Gate is systemware program by Microtech. By incorporating Invisibility and VR subroutines into the programming structure of the standard code gate, Microtech has created a CodeGate that is invisible to most normal interfaces! While more expensive than the standard code gate, it allows you to purchase lower strength gates (he can't try and crack what he can't see). You can also conceal parts of your DataFortress from you own employees (so those areas holding the Black files won't be nosed around in by your own people). Shrouded gates are invisible for all intents and purposes. A SeeYa (or other detection program specifically designed to reveal Invisible programs) gets a chance to reveal them, but otherwise they are impossible to detect.

Source

 * Rache Bartmoss Guide to the Net, pg.149