Advanced stream format (asf) data stream header object protection

A method for validating a digital signature for use with an object comprising a plurality of sub-objects and is implemented by at least one computing system, said method comprising:

• identifying at least one region corresponding to a region specifiers, where each of said region specifiers comprises a checksum calculated according to a checksum algorithm, and the region comprises all or part of one of at least one sub-object within said plurality of sub-objects;
• creating an object comprising an array comprising, for each of said region specifiers, said region corresponding to said region specifier;
• validating said digital signature on said object for said at least one region, wherein said sub-objects are rearrangable within the object without invalidating the digital signature;
• and
• storing said header object in memory.

A method for validating a digital signature for use with an object comprising a plurality of sub-objects and is implemented by at least one computing system, said method comprising:

• determining a number of digital signatures present in said object, wherein at least one region comprises all or part of one of at least one sub-object of the plurality of sub-objects and an array comprises region specifiers for each of said at least one region, each region specifier comprising a checksum calculated according to a checksum algorithm;
• validating each of said digital signatures for at least one region, wherein said sub-objects are rearrangable within the object without invalidating the digital signature;
• and
• and storing said object in memory.

A computer-readable storage medium for use with an object comprising a plurality of sub-objects, said computer-readable storage medium providing a digital signature for at least one region, where said at least one region is comprised of all or part of one of at least one sub-object within said plurality of sub-objects, the computer-readable storage medium comprising instructions for:

• creating an array comprising, for said at least one region, a region specifier identifying the region, where each of said region specifiers comprises a checksum calculated according to a checksum algorithm;
• producing the digital signature based on data comprising each region and said array;
• and
• adding a signature sub-object comprising said array and said digital signature to the object, where said sub-objects within the object may be rearranged within the object without invalidating the digital signature.

A system for use with a header object comprising a plurality of sub-objects, the system comprising:

• array-creation means for creating an array comprising, for each of at least one region, a region specifier identifying the region, wherein each of said at least one region is comprised of all or part of one of at least one sub-object within said plurality of sub-objects;
• signing means for producing a digital signature based on data comprising each region and said array;
• and
• signature-sub-object adding means for adding a signature sub-object comprising said array and said digital signature to the header object, wherein said sub-objects may be rearranged within the header object without invalidating the digital signature.

A system for use with a header object comprising a plurality of sub-objects the system comprising:

• region-identifying means for identifying at least one region that comprises all or part of one of at least one sub-object within said plurality of sub-objects, wherein an array comprises region specifiers for each of said at least one region;
• data object creation means for creating a digital signature sub-object comprising said array and, for each of said region specifiers, said region corresponding to said region specifier;
• and
• validation means for validating a digital signature on said data object for at least one region, wherein the sub-objects are rearrangeable within the header object without invalidating the digital signature.