Platform Boot Firmware Hash Verification for Secure Fast Boot
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Solution Overview
Problem
Existing device activation methods that rely on signature verification for establishing a hardware root of trust are inefficient, causing delays and increased memory usage, which negatively impact user experience and device performance.
Innovation Solution
A system that uses a hash-based verification method, where a pre-verifier verifies the signature of a hash table and calculates hashes for platform boot firmware files, allowing only files with matching hashes to execute, and performs platform-specific security actions for unverified files, thereby reducing the time and memory resources required during device activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signature verification is performed for all platform boot firmware files during device activation, then security against malware and viruses is ensured, but device startup time increases substantially
Solution Approach 1:
The verification process is segmented into two distinct phases: (1) a first phase that verifies signatures of critical firmware files using traditional cryptographic signature verification, and (2) a second phase that verifies hashes of additional firmware files using faster hash-based verification. This segmentation allows the system to apply different verification methods to different files based on their criticality, thereby maintaining security while reducing overall verification time.
Solution Approach 2:
The verification parameter is changed from cryptographic signature verification (which is computationally intensive and time-consuming) to hash-based verification (which is faster) for the second phase of firmware verification. By changing the verification parameter from signature to hash for certain files, the system achieves faster verification speeds while maintaining adequate security through the combination of both verification methods.
2Reliability
If signature verification is performed for all platform boot firmware files during device activation, then file authenticity is ensured, but memory resources used increase substantially
Solution Approach 1:
The firmware verification process is segmented into two phases with different resource requirements. The first phase loads and verifies signatures of critical files, while the second phase verifies hashes of additional files. This segmentation allows memory resources to be managed more efficiently by processing files in batches rather than loading all files simultaneously into memory for signature verification.
Solution Approach 2:
The patent uses hash values as a lighter, more efficient alternative to full cryptographic signatures for the second phase of verification. Hash values require less memory to store and process compared to full digital signatures, making them a 'cheaper' verification mechanism in terms of memory resources while still providing adequate authenticity verification for non-critical firmware files.
3Reliability
If signing is conducted serially for all files to be loaded from platform boot firmware, then all files are validated, but both memory and time requirements increase substantially
Solution Approach 1:
The serial signing process is divided into two phases: the first phase performs signature verification on critical firmware files, and the second phase performs hash verification on additional firmware files. This segmentation enables parallel processing capabilities where multiple files can be verified concurrently in the second phase, significantly improving device activation speed while maintaining comprehensive file validation.
Solution Approach 2:
The verification process is structured as periodic action with two distinct verification cycles: the first cycle performs signature verification on critical files, and the second cycle performs hash verification on additional files. This periodic structure allows the system to manage verification tasks in manageable batches, improving overall processing efficiency and device activation speed.
Data Source
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AI summary
This disclosure is directed to continuation of trust for platform boot firmware. A device may comprise a processing module and a memory module including read-only memory (ROM) on which is stored platform boot firmware. On activation, the processing module may load the platform boot firmware. The platform boot firmware may cause the processing module to first load a trusted pre-verifier file to load and verify the signature of a hash table loaded from the platform boot firmware. The processing module may then load firmware program files from the platform boot firmware, calculate a hash for each file, and verify whether each program hash is in the hash table. Firmware program files with hashes in the hash table may be allowed to execute. If any firmware program file hash is not in the hash table, the processing module may perform platform specific security actions to prevent the device from being compromised.