Passcodes are a central feature in SecurityCraft and are used throughout the mod. They often will be used to restrict access to a block's features or inventory only to players who know the correct Passcode. Passcodes are comprised of numerical digits, and can be up to eleven characters long. Any block that uses a Passcode will require it to be set by the Owner when the block is initially placed down. Codebreakers can be used to instantly "crack" a Passcode and give the wielder easy access to a block, however, the Codebreaker is expensive and has limited uses. If the Owner of a Passcode-protected block is unhappy with its code or has forgotten it, they can use a Universal Key Changer to change it.
- In early versions of SecurityCraft, Passcodes used to be stored in a .txt file in the /saves folder for the world the user was playing in. Anyone who had access to this folder would have been able to easily find all the Passcodes for every Passcode-protected block in that world.