https://simonwaite.com/tags/tempest/ Recent content in Tempest on Simon Waite Hugo en-us Mon, 01 Jul 2013 12:00:00 +0000 https://simonwaite.com/posts/air-gapped-communication/ Mon, 01 Jul 2013 12:00:00 +0000 https://simonwaite.com/posts/air-gapped-communication/ <p>Post date: Jul 01, 2013 12:00:00 PM</p> <p>By definition air-gapped devices are on a separate network from the rest of the internet.</p> <p>How could you communicate from an air gapped machine to the rest of the world?</p> <p>(Based on a conversation I had with an author in 2013)</p> <h3 id="power-modulation">Power Modulation</h3> <p>Modulating the current consumption of a computer would make a device capable of measuring the load on a buildings power supply detect the presence of a program modulating the load on a computer (CPU load, Disk activity, GPU load, etc). You could possibly defend against this by isolating the machine from the power supply of the building by inserting a UPS or just have it run from a generator. Bandwidth - extremely low, unidirectional.</p>