Tamper resistance is resistance to tampering by either the normal users of a product, package, or system or others with physical access to it. There are many reasons for employing tamper-resistance.
Tamper resistance ranges from simple features like screws with special heads to more complex devices that render themselves inoperable or encrypt all data transmissions between individual chips. Tamper resistant devices or features are also common on packages to deter package or product tampering.
In some applications, devices are only tamper-evident rather than tamper-resistant. Tamper-evident describes a device or process that makes unauthorised access to the protected object easily detected
Tampering involves the deliberate altering or adulteration of a product, package, or system. Solutions may involve all phases of product production, packaging, distribution, logistics, sale, and use. Packaging is the science art and technology of enclosing or protecting products for distribution storage sale and use Logistics is the management of the flow of Goods, Information and other resources including Energy and people between the point of origin and the point No single solution can be considered as "tamper proof". Often multiple levels of security need to be addressed to reduce the risk of tampering. Security is the condition of being protected against danger loss and criminals Some considerations might include:
Nearly all mains appliances and accessories can only be opened with the use of a screwdriver (or a substitute item such as a nail file or kitchen knife). This prevents children and others who are careless or unaware of the dangers of opening the equipment from doing so and hurting themselves (from electrical shocks, burns or cuts, for example) or damaging the equipment. Sometimes (especially in order to avoid litigation), manufacturers go further and use tamper resistant screws, which cannot be unfastened with standard equipment. In law a lawsuit is a civil action brought before a Court in which the party commencing the action the Plaintiff, seeks a legal or equitable remedy Tamper resistant screws are also used on electrical fittings in many public buildings primarily 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. Tamper-evident seals may be enough to deal with this. Tamper-evident describes a device or process that makes unauthorised access to the protected object easily detected However, they can't easily be checked remotely, and many countries have statutory warranty terms that mean manufacturers may still have to service the equipment. Tamper proof screws will stop most casual users from tampering in the first place.
Tamper-resistant microprocessors are used to store and process private or sensitive information, such as private keys or electronic money credit. A microprocessor incorporates most or all of the functions of a Central processing unit (CPU on a single Integrated Public-key cryptography, also known as asymmetric cryptography, is a form of Cryptography in which the key used to encrypt a message differs from the key Electronic money (also known as e-money, electronic cash, electronic currency, digital money, digital cash or digital currency To prevent an attacker from retrieving or modifying the information, the chips are designed so that the information is not accessible through external means and can be accessed only by the embedded software, which should contain the appropriate security measures.
Examples of tamper-resistant chips include all secure cryptoprocessors, such as the IBM 4758 and chips used in smartcards, as well as the Clipper chip. A secure cryptoprocessor is a dedicated Computer or Microprocessor for carrying out Cryptographic operations embedded in a packaging with multiple The IBM 4758 PCI Cryptographic Coprocessor is a Secure cryptoprocessor implemented on a high-security programmable A smart card, chip card, or Integrated circuit card ( ICC) is any pocket-sized card with embedded integrated The Clipper chip is a Chipset that was developed and promoted by the U
It has been argued that it is very difficult to make simple electronic devices secure against tampering, because numerous attacks are possible, including:
Tamper resistant 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. In Cryptography, power analysis is a form of Side channel attack in which the attacker studies the power consumption of a cryptographic hardware device (such In Cryptography, zeroisation (also spelled zeroization) is the practice of erasing sensitive parameters (especially keys from a cryptographic module to In Cryptography, a key is a piece of information (a Parameter) that determines the functional output of a cryptographic algorithm A chip may even be rated for "cold zeroisation", the ability to zeroise itself even after its power supply has been crippled.
Nevertheless, the fact that an attacker may have the device in his possession for as long as he likes, and perhaps obtain numerous other samples for testing and practice, means that it is practically impossible to totally eliminate tampering by a sufficiently motivated opponent. Because of this, one of the most important elements in protecting a system is overall system design. In particular, tamper resistant systems should "fail gracefully" by ensuring that compromise of one device does not compromise the entire system. This article contains specific implementations of fault tolerant systems In this manner, the attacker can be practically restricted to attacks that cost less than the expected return from compromising a single device (plus, perhaps, a little more for kudos). Kudos is a program used mostly in schools for young people deciding on their career choices and what qualifications they may need to get reach careers 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.
Tamper resistance finds application in smart cards, set-top boxes and other devices that use digital rights management. A smart card, chip card, or Integrated circuit card ( ICC) is any pocket-sized card with embedded integrated A set-top box (STB or set-top unit (STU is a device that connects to a Television and an external source of signal, turning the signal into Digital rights management ( DRM) is a generic term that refers to Access control technologies used by hardware manufacturers publishers and Copyright holders In this case the issue is not about stopping the user breaking the equipment or hurting themselves but about either stopping them extracting codes or acquiring and saving the decoded bitstream. This is usually done by having lots of features on each chip and making sure the busses between chips are encrypted.
DRM mechanisms also use certificates and asymmetric Key cryptography in many cases. In all such cases, tamper resistance means not allowing access to the valid device certificates/ public-private keys of the device to the device user. The process of making software robust against tampering attacks is referred to as software anti-tamper. Tamper resistance is resistance to tampering by either the normal users of a product package or system or others with physical access to it
In the design of nuclear reactors, preventing the proliferation of nuclear weapons has become rather important. This article is a subarticle of Nuclear power. A nuclear reactor is a device in which Nuclear chain reactions are initiated controlled A nuclear weapon is an explosive device that derives its destructive force from Nuclear reactions either fission or a combination of fission and fusion. Making reactors tamper-resistant, as in the SSTAR, has become fairly important. SSTAR is an acronym for the "small sealed transportable autonomous reactor " - being primarily researched and developed in the USA by Lawrence Livermore This will probably be achieved through a combination of making it difficult to get at the nuclear material, closely tracking where the reactors are transported and having alarms if attempts at entry are detected (which can then be responded to by the military).
Resistance to tampering can be built in or added to packaging. Packaging is the science art and technology of enclosing or protecting products for distribution storage sale and use Consider:
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 (removing a restriction on how it can be used, for example). Reverse engineering (RE is the process of discovering the technological principles of a device object or system through analysis of its structure function and operation One commonly used method is code obfuscation. Obfuscated code is Source code or Intermediate language that is very hard to read and understand often intentionally
However, effective tamper resistance in software is much harder than in hardware, as the software environment can be manipulated to near-arbitrary extent by the use of emulation.
If implemented, trusted computing would make software tampering of protected programs at least as difficult as hardware tampering, as the user would have to hack the trust chip to give false certifications in order to bypass remote attestation and sealed storage. Trusted Computing (TC is a technology developed and promoted by the Trusted Computing Group. However, the current specification makes it clear that the chip is not expected to be tamper-proof against any reasonably sophisticated physical attack; that is, it is not intended to be as secure as a tamper-resistant device.