Method and system for ensuring sequential playback of digital media
AssigneeApple Inc.
InventorsAram LINDAHL, Bryan J. JAMES
Life of this patent
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Abstract
Techniques for ensuring that media playback proceeds sequentially through media content of a digital media asset are disclosed. In one embodiment, distinct portions (e.g., segments) of a digital media asset can be separately encrypted such that on playback decoded data being output from at least one prior portion can be used to derive a cryptographic key that is used in decrypting a subsequent portion of the digital media asset.
Claims20
A method for requiring a media asset to be played back sequentially, the method comprising:
- dividing the media asset into a plurality of segments;
- generating corresponding encryption keys for the plurality of segments, wherein, when a segment is not a first segment of the plurality of segments, the corresponding encryption key is based in part on a previous segment;
- encrypting the plurality of segments in accordance with the corresponding encryption keys to produce a plurality of encrypted segments;
- generating decryption information for decrypting the plurality of encrypted segments;
- combining a first encryption key that corresponds to the first segment, the plurality of encrypted segments, and the decryption information to produce a protected media asset;
- and
- storing the protected media asset.
A non-transitory computer readable storage medium configured to store instructions that, when executed by a processor included in a computing device, cause the computing device to carry out steps that include:
- dividing a media asset into a plurality of segments;
- generating corresponding encryption keys for the plurality of segments, wherein, when a segment is not a first segment of the plurality of segments, the corresponding encryption key is based in part on a previous segment;
- encrypting the plurality of segments in accordance with the corresponding encryption keys to produce a plurality of encrypted segments;
- generating decryption information for decrypting the plurality of encrypted segments;
- combining a first encryption key that corresponds to the first segment, the plurality of encrypted segments, and the decryption information to produce a protected media asset;
- and
- storing the protected media asset.
A computing device, comprising:
- a processor configured to cause the computing device to carry out steps that include:
- dividing a media asset into a plurality of segments;
- generating corresponding encryption keys for the plurality of segments, wherein, when a segment is not a first segment of the plurality of segments, the corresponding encryption key is based in part on a previous segment;
- encrypting the plurality of segments in accordance with the corresponding encryption keys to produce a plurality of encrypted segments;
- generating decryption information for decrypting the plurality of encrypted segments;
- combining a first encryption key that corresponds to the first segment, the plurality of encrypted segments, and the decryption information to produce a protected media asset;
- and
- storing the protected media asset.
Dependencies are inferred from the claim text.