To counter fault analysis attacks, it is recommended to use redundancy to catch injected faults. For certain critical functions that need protected against fault-based side channel attacks, it is recommended to deploy multiple implementations of the same function. Given an input, the spacecraft can process it using the various implementations and compare the outputs. A selection module could be incorporated to decide the valid output. Although sensor nodes have limited resources, critical regions usually comprise the crypto functions, which must be secured.
|Threat actors may use a side-channel attack attempts to gather information or influence the program execution of a system by measuring or exploiting indirect effects of the spacecraft. Side-Channel attacks can be active or passive. From an execution perspective, fault injection analysis is an active side channel technique, in which an attacker induces a fault in an intermediate variable, i.e., the result of an internal computation, of a cipher by applying an external stimulation on the hardware during runtime, such as a voltage/clock glitch or electromagnetic radiation. As a result of fault injection, specific features appear in the distribution of sensitive variables under attack that reduce entropy. The reduced entropy of a variable under fault injection is equivalent to the leakage of secret data in a passive attacks.