Key Attestation Certificate Selection via Trusted Application
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Solution Overview
Problem
Existing solutions face challenges in determining which device certificate to use for signing attestation certificates during key pair generation and attestation, especially when multiple certificates are available on a device.
Innovation Solution
A device with a secure environment and multiple device certificates, where a trusted application can receive a key pair generation and attestation request with an indication of a preferred device certificate, and sign the attestation certificate using the specified certificate, optionally with cryptographic verification to ensure correct selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple device certificates are configured on a device, then the security and versatility of key pair attestation is improved, but the complexity of selecting which certificate to use for signing increases
Solution Approach 1:
The patent introduces an intermediary mechanism (the trusted application and challenge parameter system) that mediates between the multiple device certificates and the attestation process. The challenge parameter acts as a mediator that carries selection information from the requesting party through to the certificate selection logic, resolving the complexity of direct certificate management while maintaining security.
Solution Approach 2:
The patent applies preliminary action by pre-configuring multiple device certificates on the device before attestation is needed. The challenge parameter is also prepared in advance by the requesting party to indicate the preferred certificate. This preliminary setup eliminates the need for complex real-time decision-making during the attestation process itself.
2Adaptability or versatility
If a challenge parameter is used to indicate preferred device certificate, then the flexibility of certificate selection is improved, but the difficulty of detecting and measuring the correct certificate increases
Solution Approach 1:
The patent implements feedback by including the challenge parameter in the attestation certificate itself. The requesting party sends their preferred certificate indication through the challenge parameter, and this feedback loops back into the generated attestation certificate, allowing verification that the correct certificate was selected and used for signing.
3Reliability
If device certificates are enrolled during manufacturing, then the security of key pair generation is improved, but the loss of time for certificate management increases
Solution Approach 1:
The patent applies preliminary action by enrolling device certificates during the manufacturing process rather than requiring post-deployment certificate management. This upfront preparation secures the key pair generation capability while eliminating time-consuming certificate management operations that would otherwise be needed during device operation or updates.
Data Source
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AI summary
According to an aspect, a device with key attestation features is provided. The device comprises an operating system stored in its memory, the operating system comprising a secure environment including a trusted application, and two or more device certificates, each associated with a device key pair, stored in the memory of the device. The trusted application is configured to handle key pair generation requests and key pair attestation requests to read an indication of a preferred device certificate. An attestation certificate that is generated in response to the key pair attestation request is then signed using one of the two or more device certificates with its associated device key pair based on the indication of a preferred device certificate.