Data-Dependent Authentication Keys for DPA Resistance
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Solution Overview
Problem
Current systems are vulnerable to side channel attacks, particularly differential power analysis (DPA), due to side channel leakage from devices, which can compromise authentication keys and lead to tampered data manipulation, and existing solutions either increase processing time, energy usage, or system complexity.
Innovation Solution
A data-dependent authentication key generation system that employs fast mixing functions, such as XOR trees, substitution-permutation networks, and double-mix Feistel networks, to scramble authentication keys, making them dependent on protected data and reducing side channel leakage, while maintaining low processing time and energy usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional MAC generation using constant authentication keys is used, then the system is vulnerable to differential power analysis attacks due to side channel leakage, but changing the authentication key to be data-dependent increases processing time and system complexity
Solution Approach 1:
The patent applies dynamics by transforming the authentication key from a static constant value to a dynamic data-dependent value. The authentication key is generated by combining a base key with a hash of the protected data, making it change with each different data input. This dynamic key generation prevents DPA attacks because the key varies with data, eliminating the consistent patterns that DPA exploits, while the complexity increase is managed through efficient hash function implementation.
Solution Approach 2:
The patent changes the parameter of the authentication key from constant to variable based on data characteristics. By incorporating a hash function that processes the protected data and combines it with the base key, the authentication key parameters change dynamically. This parameter change ensures that even identical plaintexts produce different authentication keys, preventing side channel leakage patterns from being consistent and thus thwarting DPA attacks.
2Reliability
If data-dependent authentication keys are implemented to prevent side channel attacks, then security is improved, but processing time increases
Solution Approach 1:
The patent applies preliminary action by pre-computing and storing a hash of the protected data that will be used to generate the authentication key. This pre-computed hash is then combined with the base key to create the authentication key. By performing the hash computation in advance and reusing it where applicable, the processing time overhead is minimized while still achieving the security benefit of data-dependent keys that prevent DPA attacks.
3Reliability
If authentication keys are scrambled using mixing functions to reduce side channel leakage, then security against DPA attacks is enhanced, but energy consumption increases
Solution Approach 1:
The patent introduces a hash function as an intermediary between the protected data and the authentication key generation. This hash function acts as a mediator that processes the data and produces a condensed representation that is then combined with the base key. The intermediary hash function reduces side channel leakage by breaking the direct relationship between data and key, while its efficient design minimizes the additional energy consumption compared to more complex scrambling mechanisms.
Data Source
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AI summary
A system and method for using mixing functions to generate and manipulate authentication keys based on the data being decrypted to mitigate the effect of side channel attacks based on differential power analysis (DPA). The mixing function may be based on a XOR tree, substitution-permutation networks, or double-mix Feistel networks. The mixing function uses some secret key material, which diversifies its behavior between different instantiations.