Challenge-Response Key Selection Against Side-Channel Cloning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing authentication protocols are vulnerable to side-channel attacks, which can lead to the retrieval of secret encryption keys and cloning of devices, compromising security.
Innovation Solution
Implement a key selection algorithm that dynamically selects cryptographic keys from a set or subset of keys for each challenge-response round, using a shared key selection algorithm with an external device, and optionally incorporating device identifiers and randomization keys to randomize the key selection process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single cryptographic key is used for all challenge-response rounds, then the authentication protocol is simpler to implement, but the device becomes vulnerable to side-channel attacks
Solution Approach 1:
The cryptographic key material is segmented into multiple individual cryptographic keys stored in the device. Instead of using a single key for all authentication rounds, the device maintains a plurality of distinct cryptographic keys that can be selectively used during challenge-response rounds, thereby distributing the security risk across multiple key elements.
Solution Approach 2:
The authentication protocol dynamically selects different cryptographic keys from the stored set for different challenge-response rounds. This dynamic key selection prevents attackers from analyzing consistent patterns in power consumption or electromagnetic emissions that would occur with a static key, thereby resisting side-channel attacks while maintaining protocol functionality.
2Reliability
If cryptographic keys are randomly selected for each challenge-response round, then resistance against side-channel attacks is enhanced, but the key selection process becomes more complex
Solution Approach 1:
The device pre-stores a plurality of cryptographic keys in memory before authentication begins. This preliminary preparation eliminates the need for complex real-time key generation or selection algorithms during the actual challenge-response rounds, reducing operational complexity while maintaining security through the use of pre-prepared key material.
Solution Approach 2:
Multiple copies of cryptographic key material are stored in the device, each copy being a distinct cryptographic key. This allows the authentication protocol to reference and use different key copies during different challenge-response rounds without requiring complex key derivation or generation processes, simplifying the overall key management while enhancing security through key diversity.
3Reliability
If all cryptographic keys are used in the key pool, then key diversity is maximized, but the storage requirements and processing overhead increase
Solution Approach 1:
The authentication protocol uses only a subset of the stored cryptographic keys during challenge-response rounds rather than all available keys. This partial usage maintains sufficient key diversity for security purposes while reducing the actual number of keys that need to be actively managed and processed, thereby lowering storage and computational overhead compared to utilizing the entire key pool.
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 2C~2D
AI summary
In accordance with a first aspect of the present disclosure, a communication device for use in one or more challenge-response rounds is provided, comprising: a response generation unit configured to generate, in each challenge-response round, a response to a challenge received from an external communication device, wherein said response is generated by performing a cryptographic function on said challenge, and wherein the cryptographic function takes said challenge and a cryptographic key as inputs; a key selection unit configured to select said cryptographic key from a set of cryptographic keys by executing a predefined key selection algorithm that has been shared with the external communication device. Further aspects of the present disclosure relate to another communication device for use in one of more challenge-response rounds, corresponding methods of operating communication devices, and computer programs for carrying out said methods.