Tamperproofing

Tamperproofing is a methodology used to hinder, deter or detect unauthorised access to a device or circumvention of a security system.

Since any device or system can be foiled by a person with sufficient knowledge, equipment, and time, the term "tamperproof" is a misnomer unless some limitations on the tampering party's resources is explicit or assumed.

Various other security screw heads have been devised to discourage casual access to the interior of such devices as consumer electronics.

Tamper-resistant screws are used on electrical fittings in many public buildings to reduce tampering or vandalism that may cause a danger to others.

A user who breaks equipment by modifying it in a way not intended by the manufacturer might deny they did it, in order to claim the warranty or (mainly in the case of PCs) call the helpdesk for help in fixing it.

However, they cannot easily be checked remotely, and many countries have statutory warranty terms that mean manufacturers may still have to service the equipment.

[citation needed] Nevertheless, the fact that an attacker may have the device in their possession for as long as they like, and perhaps obtain numerous other samples for testing and practice, means that it is impossible to totally eliminate tampering by a sufficiently motivated opponent.

Since the most sophisticated attacks have been estimated to cost several hundred thousand dollars to carry out, carefully designed systems may be invulnerable in practice.

[1] Tamper resistance finds application in smart cards, set-top boxes and other devices that use digital rights management (DRM).

[3] Examples include: Software is also said to be tamper-resistant when it contains measures to make reverse engineering harder, or to prevent a user from modifying it against the manufacturer's wishes (such as removing a restriction on how it can be used).

However, the current specification makes it clear that the chip is not expected to be tamper-proof against any reasonably sophisticated physical attack;[4] that is, it is not intended to be as secure as a tamper-resistant device.