Air gap

from Wikipedia, the free encyclopedia

As an air gap (English for "air gap") or airwall (English for "air wall", in analogy to a firewall , the purpose of which is similar) is a process in computer science that physically and logically separates two IT systems from one another, but nevertheless allows the transmission of user data .

An air gap is used to isolate two or more differently trustworthy computers or computer networks from each other, but which have to process data from the other system.

realization

An air gap is often implemented as a process in which data is transferred by transporting a storage medium. A transportable medium is inserted into the source system, written to there, removed from it and inserted into the target system, where the content is read and processed. The benefit lies in the isolation of the systems from each other:

  • The possibility of data transmission in only one direction can be guaranteed.
  • The target system cannot be addressed by the source system (s).
  • Even with the transmission of malware or the like (provided the target system does not have a connection to a corresponding computer network such as the Internet), there is no return channel available that could, for example, enable the transmission of confidential content.

In addition to the implementation as a process, there are technical implementations of the air gap concept:

  • the e-Gap products from Microsoft (formerly Whale Communications )
  • the reflective gap products from Spearhead Technologies Inc.
  • the data diode products from Owl Computing Technologies Inc.
  • the Interactive Link Data Diode from BAE Systems Australia (formerly Tenix Datagate )
  • the lock-keeper technology from Siemens
  • the Waterfall products from Waterfall Security Solutions

Circumvention measures

Since November 2013, scientists have shown that air gaps can be tricked using various methods.

  • In this way they can be overcome by means of hidden acoustic networks.
  • The graphics card of a computer can also be used to generate a radio signal.
  • The air gap can even be overcome through temperature changes.
  • Information can also be spied on via GSM devices (such as cell phones).
  • Small amounts of data can also be transmitted through the noise of a hard disk read / write head
  • Another point of attack is an optical transmission via manipulated hard disk activity indicators or other LEDs that are visible from the outside
  • The processor of a personal computer can be used to emit radio waves.

See also

Individual evidence

  1. ↑ Airwall . (English-language Wiktionary)
  2. ↑ Volker Weber: Microsoft buys firewall specialist Whale Communications . Heise News, May 19, 2006
  3. ↑ Michael Hanspach, Michael Goetz: On Covert Acoustical Mesh Networks in Air . In: Engineering and Technology Publishing (Ed.): Journal of Communications . 8, No. 11, November 2013, pp. 758-767. doi : 10.12720 / jcm.8.11.758-767 . Retrieved November 22, 2013.
  4. ↑ Gerald Himmelein: Super Trojans BadBIOS: Unlikely, but possible . Heise News , November 11, 2013
  5. ↑ Ronald Eikenberg: Graphics card transmits passwords around . Heise News, November 30, 2014
  6. ↑ Heise News: BitWhisper overcomes the air gap with temperature fluctuations , by Fabian Scherschel, March 25, 2015
  7. ↑ Ute Roos: Researchers succeed in stealing data from offline computers . Heise News, July 29, 2015
  8. ↑ The purring of a hard drive reveals secrets. In: heise Security. Retrieved September 5, 2016 .
  9. ↑ How computer LEDs can flash secrets to the outside world. In: Spiegel Online netzwelt. Retrieved February 23, 2017 .
  10. ↑ heise online: PC and notebook send medium wave via JavaScript. Retrieved January 25, 2018 (German).