AACS Media Key Block Update Logic for Disc Capacity Conservation
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Solution Overview
Problem
The frequent updating of Media Key Block (MKB) in the AACS system leads to a decrease in system response due to unnecessary writing of MKB even when no content is being protected, resulting in wasteful consumption of disc capacity and inefficient operations.
Innovation Solution
Implementing a method to only write MKB onto a medium when contents have been recorded, and ensuring the latest MKB is updated only when necessary, by comparing the versions of Lead-in MKB, Device MKB, and Read Write MKB, and writing MKB only when content-related files like the title key file and title usage file are present.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MKB is frequently updated to maintain content protection functionality, then security reliability is improved, but system response speed deteriorates due to unnecessary write operations
Solution Approach 1:
The patent implements conditional MKB updates by checking whether title key files and title usage files are present before performing write operations. This partial action approach updates MKB only when content protection is actually required, avoiding excessive updates that would slow down system response while maintaining security reliability when needed.
Solution Approach 2:
The patent changes the operational parameter of MKB updates from a fixed frequent schedule to a conditional trigger-based approach. By monitoring the presence of content-related files as a parameter change condition, the system dynamically adjusts when updates occur, balancing security requirements with system performance.
2Reliability
If MKB is updated frequently to ensure latest security, then security effectiveness is improved, but disc capacity is wasted due to unnecessary write operations
Solution Approach 1:
The patent applies partial action by performing MKB updates only when content-related files are detected. This prevents excessive write operations that would waste disc capacity while ensuring security effectiveness is maintained through targeted updates when actually needed for content protection.
Solution Approach 2:
The patent implements a feedback mechanism by checking the presence of title key files and title usage files before triggering MKB updates. This feedback loop ensures updates occur only when content protection is required, preventing disc capacity waste from unnecessary writes while maintaining security effectiveness.
3Reliability
If MKB update operations are performed continuously, then content protection is maintained, but operational efficiency deteriorates
Solution Approach 1:
The patent eliminates excessive MKB update operations by implementing conditional logic that checks for the presence of content-related files. This partial action approach maintains content protection reliability through necessary updates while dramatically improving operational efficiency by avoiding continuous unnecessary write operations.
Solution Approach 2:
The system performs self-service by automatically detecting when content-related files are present and triggering MKB updates only in those conditions. This self-regulating mechanism maintains content protection while optimizing operational efficiency without requiring external control or continuous manual intervention.
Data Source
AI summary
According to one embodiment of the invention, there is provided an information recording and reproducing apparatus which records information in a recording medium and reproduces information recorded in the recording medium, the information recording and reproducing apparatus includes a first recording section which records in the recording medium an encrypted encryption key aggregate where at least one encryption key for encrypting each of a plurality of pieces of information has been encrypted and registered and information encrypted using the encryption key, a second recording section which records encrypted first private key information used to encrypt or decrypt the encryption key into the recording medium and which, if the encrypted encryption key aggregate has not been recorded in the recording medium, records the first private key information into the recording medium only when the encrypted encryption key aggregate is recorded in the recording medium.