15" G4 iMac: iChastity Security Frame

By: Mikio Moriyasu - Revised: 2006-06-22 devin


Prior to their deployment in the Union Building on the first and second floors of the South hall and in the downstairs CyberCafe, the flat-panel iMacs had to be secured against theft and tampering.

The main focus was to find a way to lock each machine down to the tables and desks as well as prevent access to the bottom panel and the additional RAM. A number of security options were examined to this end including:
  • Replacing the existing screws for the bottom access plate with security screws.
  • Sealing the existing screws in place by covering them with epoxy.
  • Replacing the existing screws for the bottom access plate with extra long security screws that would bolt the machine to the table as well as secure the bottom plate
  • Locking the iMac into a custom device that bolts it to the table.
Each of the above options, however, had certain drawbacks.
  • None of the available security screws were an exact match to the iMac screws. Using them would have meant stripping the threads in the existing screw openings damaging them and voiding the warrantee.
  • Epoxy once applied is very difficult to remove. Any repairs to the machine would require the use of dry ice to freeze the epoxy so that it could be broken off and the screws removed.
  • Bolting each machine to the desk by driving screws through the table into the bottom of the machine could also damage the existing screw openings but would certainly require damaging modifications to the tables themselves.
  • None of the existing custom security devices, offered what we thought was adequate, robust protection at an affordable price. In addition, securing these devices to the tables would also require invasive modifications.
In the end, we commissioned the University of Utah Machine Shop to construct "iChastity"- a lightweight security frame that "wraps" around the hemispherical base of the iMac.


One of the frame members is hinged and can be opened to allow the iMac to be inserted. The hinged portion can then locked to the rest of the frame at the base of the iMac "neck". The frame itself is secured to the tables with a length of heavy gauge chain.


This solution achieves the goal of securing each machine to the tables and prevent access to the bottom panel. It is "non-invasive" however, and does not require any damaging physical modifications to the tabletop surfaces, or to the machine itself.