PMT Packet Fixing Information for Content Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional content protection systems, such as AACS, are vulnerable to frequent hacker attacks during content reproduction, as they do not effectively prevent deactivation of region codes or security measures, especially when simple control commands are used, leading to potential content theft.
Innovation Solution
The method involves scrambling specific parts of content and storing fixing information in a program map table (PMT) packet, which includes location information for subsequent PMT packets containing fixing data, allowing for selective fixing of transformed content without parsing all packets, thereby enhancing security and reducing system load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional content protection systems (AACS) are used, then content encryption and device key management are provided, but the system is vulnerable to hacker attacks and cannot prevent deactivation of region codes or security measures
Solution Approach 1:
The patent segments the content into multiple packets and applies different protection mechanisms to different segments. The security code is divided into multiple pieces distributed across different packets, and the Program Map Table is segmented to include location information of subsequent packets containing fixing data. This segmentation prevents hackers from easily deactivating the entire protection system by targeting individual segments rather than the whole system.
Solution Approach 2:
The patent performs preliminary actions by pre-storing fixing information and location information in the Program Map Table before content reproduction. The fixing data is prepared in advance in subsequent packets, and the location information is embedded beforehand to guide the retrieval process. This preliminary preparation ensures that when content is reproduced, the fixing process can be executed quickly and reliably without delaying the playback.
2Reliability
If security code continuously descrambles content, then content protection against hacking is enhanced, but system load and processing complexity increase
Solution Approach 1:
The patent extracts only the necessary fixing information and location information from the content packets and stores them in the Program Map Table. Instead of continuously processing and descrambling the entire content stream, the system extracts and applies fixing data only at specific locations indicated by the location information. This extraction approach reduces the processing load while maintaining effective content protection.
Solution Approach 2:
The patent applies partial action by selectively fixing only the transformed parts of the content rather than processing the entire content stream. The security code continuously descrambles content, but the fixing operation is applied partially only to the specific packets identified by location information, reducing the overall system load while maintaining protection effectiveness.
3Productivity
If fixing information is stored in Program Map Table packets, then selective fixing of transformed content is enabled, but packet structure and data organization become more complex
Solution Approach 1:
The patent merges the fixing information and location information directly into the existing Program Map Table packet structure. Instead of creating separate data structures or files, the patent combines multiple pieces of information (fixing data, location information, and existing packet metadata) into a unified packet format. This merging approach enables selective fixing efficiency while minimizing the increase in structural complexity by utilizing existing packet frameworks.
Data Source
AI summary
Provided are a method and apparatus for effectively fixing scrambled content. The method includes checking fixing information for a program map table (PMT) packet of packets constituting the content, the fixing information being used to fix a transformed part of the content; extracting location information of a next PMT packet containing fixing data for fixing the transformed part of the content from the fixing information of the PMT packet; and fixing the transformed part of the content by using the fixing data in the next PMT packet indicated by the extracted location information. Accordingly, it is possible to easily detect a location of the content, which stores the fixing information, thereby expediting fixing of the transformed content.