System Key
System Keys are rare electronic components used to create one-time hacks such as Blackout, Jam Comms and CTOS Scans.
How to Find[]
System Keys are normally found during missions in hidden locations, or found on a civilian who holds them. It would be easier to find a system key on civilians by upgrading the Profiler Optimization skill to improve your chance of finding them.
Raymond Kenney is able to purchase System Keys in Pawn Shops, where they come on a blue USB stick.