Challenge-Response Authentication Using Keyed Response Delays
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Solution Overview
Problem
Existing authentication methods in low-power devices are limited by fixed key sizes and computational resources, making it difficult to enhance security and detect device clones, while maintaining compatibility with standard cryptographic protocols.
Innovation Solution
A challenge-response authentication method that incorporates a delay computation function using a secondary key to increase the effective key size, allowing detection of illegitimate devices by verifying the arrival time of responses within a distribution interval, and optionally updating the secondary key after each use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the key size is increased to enhance authentication strength, then security is improved, but computational resources (time, energy, memory) are consumed excessively
Solution Approach 1:
The authentication key is segmented into two separate keys: a first key used for standard cryptographic authentication and a second key used for computing response delay. This segmentation allows each key to serve a specific function with optimized resource usage, avoiding the need to increase the size of a single authentication key while still enhancing overall authentication strength through the combination of both keys.
2Reliability
If the key size is increased to detect device clones, then clone detection capability is improved, but device complexity increases
Solution Approach 1:
The authentication system is segmented into two functional components: standard cryptographic verification using a first key and delay-based verification using a second key. This segmentation enables clone detection through delay verification without requiring a single complex key structure, thereby improving clone detection capability while maintaining manageable device complexity.
Solution Approach 2:
The response delay computed using the second key acts as an intermediary verification mechanism. Instead of directly increasing key size for clone detection, the system introduces a delay verification step that serves as an intermediate check, allowing legitimate devices to be distinguished from clones based on their ability to compute the correct delay, thus improving clone detection without significantly increasing device complexity.
3Adaptability or versatility
If standard cryptographic protocols are used to maintain compatibility, then interoperability is ensured, but authentication strength is limited by fixed key sizes
Solution Approach 1:
The system merges two authentication mechanisms: standard cryptographic verification (using the first key) that ensures protocol compatibility and interoperability, and delay-based verification (using the second key) that enhances authentication strength. By combining these two independent verification methods, the system maintains compatibility with standard cryptographic protocols while overcoming the limitation of fixed key sizes through the additional security layer provided by the second key.
Data Source
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AI summary
A method is provided for challenge-response authentication between a verifier and a prover. In the method, a challenge is received from the verifier, the challenge for verifying an identity of the prover. The challenge is computed using a first verifier key. The prover computes a response to the challenge using a first prover key. The prover also computes a delay time for delaying transmission of the response to the verifier using a second prover key and a delay computation function. The response is transmitted by the prover to the verifier at the computed delay time. The response is verifiable by the verifier using the first verifier key. An arrival time of the response is verifiable by the verifier using a second verifier key. In another embodiment, a device for providing a delayed response is provided.