Domain-Bound Flag Recording for Secure Content Reproduction
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Solution Overview
Problem
Conventional domain management systems struggle to update and manage content keys on external storage media in real-time, leading to issues with content reproduction when domain keys change, as the previous domain key becomes obsolete upon new key distribution.
Innovation Solution
A method is introduced to record domain management information and a domain-bound flag on storage media, ensuring that contents are only reproduced within a predetermined domain by extracting and storing domain management information and copy control details, and using these to authenticate and authorize content access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If domain key is changed when a new slave or illegally copied slave accesses the domain, then content security is improved, but the ability to reproduce previously recorded contents is lost
Solution Approach 1:
The patent records the domain key at the time of content recording onto the storage medium in advance. This preliminary action ensures that even when the domain key changes later, the originally recorded domain key remains available on the storage medium, enabling reproduction of the content without requiring real-time domain key updates.
Solution Approach 2:
The patent creates a copy of the domain key and stores it on the storage medium alongside the content. This copied domain key serves as a permanent reference that independent of subsequent domain key changes, allowing the reproducing apparatus to retrieve and use the correct domain key for decryption regardless of current domain key status.
2Reliability
If domain key is updated in real-time in the slave, then content security is maintained, but external storage medium cannot be updated when not connected to slave
Solution Approach 1:
The domain key is recorded on the storage medium during the initial content recording process, before any potential disconnection occurs. This preliminary recording ensures that the storage medium contains the necessary domain key information independently of the slave device's current state or connectivity status.
Solution Approach 2:
The storage medium becomes self-sufficient by storing the domain key locally. The reproducing apparatus can retrieve and use the domain key directly from the storage medium without requiring real-time communication with the slave device or external key management systems, enabling autonomous content reproduction.
3Reliability
If previous domain key information is deleted from slave after new domain key is provided, then domain security is improved, but conventional apparatus cannot reproduce contents
Solution Approach 1:
The patent copies the domain key to the storage medium during the recording process. This creates a permanent record of the domain key that persists independently of the slave device's key management operations, allowing reproduction even when the slave deletes previous domain key information for security reasons.
Solution Approach 2:
The domain key information is preliminarily recorded on the storage medium before the slave device performs any key rotation or deletion operations. This ensures that the reproducing apparatus has access to the necessary decryption key regardless of subsequent key management changes in the slave device.
Data Source
AI summary
Provided are a method of recording/reproducing data under control of a domain management system. The method includes extracting, from the write command, domain management information regarding the predetermined domain and contents, and copy control information specifying an extent of copying the contents within the predetermined domain; recording the extracted domain management information on the storage medium; generating a domain-bound flag that is used to determine whether the recording apparatus which records the contents on a storage medium is present in the predetermined domain, based on the extracted copy control information; and recording the domain-bound flag and the contents on the storage medium. Accordingly, it is possible to record contents, recording of which is limited within a predetermined domain, on a storage medium outside a slave under control of a domain management system, while preventing the contents from being reproduced within other domains.