At the Black Hat Security conference Cody Brocious demonstrated how you can easiy open an Onity hotel room lock, the standard system used in many hotel chains, with an Arduino but it was bulky setup and comletely obvious if anyone saw him pull out a lot of electronics. Here’s how you can fit that system in a dry erase marker.
The weblog of ethical hacker group Trustwave Spiderlabs found that the key to hiding the electronic lockpicking setup was to cut down a prototyping breadboard and move the necessary Arduino internals, a battery, a switch, and a DC coaxial barrel connector there. A dry erase marker is great for this since the barrel plug is built into the tip of the marker and be covered with the marker cap. The guys at Spiderlabs moved Cody’s Arduino sketch for duplicating the master key to the Arduino and tested that it worked on an Onity lock they purchased from eBay before cutting down the components.
The full details including the circuit diagram can be found at the source link below. Unfortunately there aren’t too many ways to use this evil hack for good other than being aware that your hotel room lock may not be providing as much security as you would expect so plan for that and don’t leave valuables behind unless using an in-room safe or other means of security