Multi-Stage Key Provisioning for IC Security
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the manufacturing of integrated circuit (IC) devices, maintaining security during the provisioning of cryptographic keys is challenging due to the risk of malicious insiders accessing key values stored in provisioning appliances, which can lead to unauthorized use and tampering if a single point of access exists.
Innovation Solution
A multi-stage provisioning approach is implemented, where two distinct keys are provisioned at different stages of the manufacturing process, with the first key being provisioned via electrical probes on a semiconductor wafer and the second key via contact pins after dicing, using separate provisioning appliances. Both keys are used to compute a digital signature for verification, ensuring that no single point of access contains all key information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cryptographic keys are provisioned in a single stage using one provisioning appliance, then the provisioning process is simple and efficient, but the security is compromised because malicious insiders can access all key values from a single point of access
Solution Approach 1:
The provisioning process is divided into multiple stages, with each stage provisioning a different key. The first key is provisioned at the wafer level during manufacturing, while the second key is provisioned after dicing at the chip level. This segmentation ensures that no single provisioning appliance has access to all key values, thereby enhancing security while distributing the complexity across multiple controlled stages.
2Reliability
If keys are provisioned at the IC manufacturing stage via electrical probes, then security is improved compared to system-level assembly, but the process requires precise wafer-level access and additional manufacturing steps
Solution Approach 1:
The first key is provisioned in advance during the wafer-level manufacturing process before the chips are diced and assembled into final products. This preliminary action allows the key to be embedded early in the manufacturing flow, enhancing security while integrating seamlessly into existing wafer-level testing and provisioning infrastructure.
3Reliability
If multiple keys are provisioned at different stages using separate appliances, then security against malicious insiders is enhanced, but the provisioning process becomes more complex and requires coordination between multiple entities
Solution Approach 1:
A secure element or trusted platform module within the device acts as an intermediary that manages multiple keys provisioned at different stages. This intermediary coordinates the provisioning process, ensuring that each key is properly installed and protected, while simplifying the overall management for multiple provisioning entities by providing a unified security interface.
Data Source
AI summary
A method for provisioning an electronic device includes providing a semiconductor wafer on which multiple integrated circuit (IC) chips have been fabricated. Each chip includes a secure memory and programmable logic, which is configured to store at least two keys in the secure memory and to compute digital signatures over data using the at least two keys. A respective first key is provisioned into the secure memory of each of the chips via electrical probes applied to contact pads on the semiconductor wafer. After dicing of the wafer, a respective second key is provisioned into the secure memory of each of the chips via contact pins of the chips. A respective provisioning report is received from each of the chips with a digital signature computed by the logic using both of the respective first and second keys. The provisioning is verified based on the digital signature.