In the field of computer security, system hardware is said to be tamper-resistant if it is difficult to modify or subvert, even for an assailant who has physical access to the system. A common form of tamper-resistance is a device or sub-system which contains information which is difficult to extract even with direct physical access. Tamper resistance finds application in smart cards, set-top boxes and other devices that use digital restrictions management.
It has been argued that it is very difficult to make simple electronic devices secure against tampering, because numerous attacks are possible, including :
physical attack of various forms (drills, files, solvents, etc)
freezing the device
applying out-of-spec voltages or power surges
applying unusual clock signals
inducing software errors using radiation
measuring the precise time and power requirements of certain operations (see power analysis)
IBM has, however, challenged this argument by developing the 4758secure cryptoprocessor, which includes defences against numerous mechanical, chemical, electrical, and radiological attacks. Despite some hiccups, it appears possible that such systems could be impenetrable to adversaries with limited time or resources. In practice, this may be sufficient under many circumstances.
References
Sean Smith & Steve Weingart, Building a High-Performance, Programmable Secure Coprocessor (http://www.research.ibm.com/secure_systems/papers/arch.pdf), Computer Networks 31, pp. 831--860 (1999)
Tamperresistance is resistance to tampering by either the normal users of the system or others with physical access to it.
Tamper proof screws are also used on electrical fittings in many public buildings primarily to stop tampering or vandalism that may cause a danger to others.
Tamperresistant chips may be designed to zeroise their sensitive data (especially cryptographic keys) if they detect penetration of their security encapsulation or out-of-specification environmental parameters.
Feeds |
Contact