Below, you can find the solution of the puzzle connected to the safe in the security office located on the first level of Talos I Lobby. Opening the safe is slightly more problematic since discovering the right keycode is not so obvious. However, the puzzle is worthwhile because the safe contains several very valuable items.
The security office can be access by walking over the yellow tube and using the small shaft or using a keycard on the reader by the door. The keycard to the Security Station can be found in the IT security room on the second level of the lobby. The safe is shown in the above picture.
Look around the safe and find the book called The Orit (shown in the image). Reading it will let you find out that the keycode is 0526. In the safe, you can find a Shotgun Shell Fabrication Plan as well as three different gadgets - Recycler Charge, Nullwave Transmitter, and an EMP Charge.