Tampering is the process of accessing or modifying goods or devices without authorization to do so. An example of tampering is opening a container to modify its contents, or a consumer electronic device in order to introduce aftermarket modifications.

Tamper Evident Devices

Certain devices or measures can be used to detect tampering. While these do not prevent the attacker from tampering with the device, they indicate to the person inspecting the Tamper Evident Device that tampering has occurred.

How this inspection is performed depends on the device being used, and the time and effort being put into the inspection. A casual inspection may only check if a seal is present or not, while an in-depth forensic inspection will go to great lengths to detect any signs of possible tampering

Examples of Tamper Evident Devices

• Stickers
• Zip-Ties
• Crimps
• Wraps
• Seals (Plastic, Metal, etc.)
• Electrical Sensors

Tamper Resistant Devices

Tamper Resistant Devices are devices that actively deter an attacker from tampering with a device. Tamper Resistant Devices do not necessarily need to be Tamper Evident Devices at the same time. An example for such a situation is a tamper-resistant slotted screw, which is a specific kind of screw that is easy to tighten with a regular slotted screwdriver, but hard to unscrew. The reason why this screw is not considered Tamper Evident is because the screw can be drilled into and removed, then replaced by an identical screw.

Examples of Tamper Resistant Devices

• Unusual Screws
• Locks
• Electronic Modules

Tamper-Proof Devices

A device claiming to be tamper proof claims that it is impossible to tamper with. This belief is generally considered marketing speak. Every device sold as "tamper proof" is either Tamper Evident and/or Tamper Resistant at best. At worst, it is trivially bypassable.