T 5.82 Manipulation of a cryptomodule

A perpetrator can attempt to manipulate a cryptomodule in order to read secret codes, alter the codes or even alter vital security parameters. A cryptomodule can be manipulated in various ways, for example it can contain:

• a super password which can get round all other passwords.

• unregistered test modes through which sensitive areas can be accessed at any time.

• Trojan horses, i.e. software which, alongside its actual task, performs actions which cannot be recognised directly, such as recording passwords.

• manipulated access rights to certain commands

. Other examples of such attacks include:

• modifying cryptographic codes,

• impairing the internal code generation, e.g. by manipulating the random number generator,

• modifying the processes within the cryptomodule,

• modifying the source code or the executable code of the cryptomodule,

• exceeding or falling below the permissible range of the cryptomodule's voltage supply, temperature, EMC limits, etc.

When the cryptomodule is manipulated, the perpetrator will usually try to conceal the attack so that the user believes the cryptomodule to be working correctly at first glance, although it is actually in an insecure state. There are, nevertheless, also destructive attacks in which perpetrators consciously resign themselves to destroying the cryptomodule, for example if they wish to obtain information on how the cryptomodule functions or read the cryptographic code.

A perpetrator can attempt to attack the cryptomodule at the user's site or steal it. If the user's site is poorly protected, the manipulation may be performed extremely rapidly and may thereby remain unnoticed for a long time. By stealing cryptomodules, a perpetrator can obtain important information on how a component can most easily be manipulated. The stolen components can be used to obtain sensitive information such as codes, software or knowledge of hardware security mechanisms. However, the stolen component can also be used to fake an authentic cryptomodule.