3 ms·

What you want is an RFID keyfob/detector. There used to be a writeup on a homebrew version of this at http://hackaday.com/2013/09/07/hidden-rfid-reader-locks-wo

What you want is an RFID keyfob/detector. There used to be a writeup on a homebrew version of this at http://hackaday.com/2013/09/07/hidden-rfid-reader-locks-workstation-unless-keys-are-present/ http://hackaday.com/2013/09/07/hidden-rfid-reader-locks-work... -- but the link that article references is rotten now. A sufficiently motivated person should be able to dig up instructions somewhere. A few years ago there were companies that did this for most operating systems, and fairly inexpensively too, but I'm having trouble finding them now.

bigbugbag 12y ago
Anything rfid can easily be duplicated.
- padelt 12y ago
  A simple readonly RFID tag - agreed. But think "smartcard with wireless power transmission" like [1]. These should be able to ensure cryptographically secure communication and identification. At least MitM-attacks without physical access to the card should be unfeasible, right? [1] http://en.wikipedia.org/wiki/Contactless_smart_card#Security http://en.wikipedia.org/wiki/Contactless_smart_card#Security
  - thaumaturgy 12y ago
    I don't think perfect security needs to be the goal here. You just need to have your device automatically protect the data on it when you're separated from it -- whether it's the state in suits, or just random laptop theft in San Francisco. If you're up against an enemy capable of realizing ahead of time that you've RFID-protected your device, and capable of cloning your RFID tag without your knowledge, then you're probably screwed no matter what you do.
literalusername 12y ago
https://www.youtube.com/watch?v=IIEdExAOXf0 https://www.youtube.com/watch?v=IIEdExAOXf0 https://github.com/kristoffer-marshall/XScreensaver-RFID-Unlock https://github.com/kristoffer-marshall/XScreensaver-RFID-Unl... Anyone who may be logged on to multiple TTYs should prefer `vlock -an` over `xscreensaver-command --lock`.

bigbugbag 12y ago

Anything rfid can easily be duplicated.

padelt 12y ago
A simple readonly RFID tag - agreed. But think "smartcard with wireless power transmission" like [1]. These should be able to ensure cryptographically secure communication and identification. At least MitM-attacks without physical access to the card should be unfeasible, right? [1] http://en.wikipedia.org/wiki/Contactless_smart_card#Security http://en.wikipedia.org/wiki/Contactless_smart_card#Security
- thaumaturgy 12y ago
  I don't think perfect security needs to be the goal here. You just need to have your device automatically protect the data on it when you're separated from it -- whether it's the state in suits, or just random laptop theft in San Francisco. If you're up against an enemy capable of realizing ahead of time that you've RFID-protected your device, and capable of cloning your RFID tag without your knowledge, then you're probably screwed no matter what you do.

literalusername 12y ago

https://www.youtube.com/watch?v=IIEdExAOXf0 https://www.youtube.com/watch?v=IIEdExAOXf0 https://github.com/kristoffer-marshall/XScreensaver-RFID-Unlock https://github.com/kristoffer-marshall/XScreensaver-RFID-Unl... Anyone who may be logged on to multiple TTYs should prefer `vlock -an` over `xscreensaver-command --lock`.