US 2006/0136723 A1 · Data processing apparatus and method

Abstract

An encoding data processing apparatus is described which is operable to generate protected compression encoded data representative of protected media signals. The apparatus comprises a data analyser which is operable to receive compression encoded data representative of the media signals and to select low perceptibility data bits in the compression encoded data which when altered would have a relatively low perceivable effect on the media signals recovered from compression decoding the compression encoded data after the selected bits had been altered. The bits are selected in accordance with predetermined criteria. The apparatus also comprises an information validation engine which is operable to form a normalised version of the compression encoded data by setting the selected data bits in the compression encoded data to a predetermined value and to generate a secure hash value of the normalised version of the compression encoded data. The information validation engine then forms the protected compression encoded data by replacing the selected data bits of the normalised compression encoded data with the data bits of the secure hash value. By generating a secure hash of the normalised bitstream rather than the original bitstream, subsequent authentication of the bitstream to verify that the bitstream has not been changed becomes possible without increasing the size of the bitstream.

Claims36

Dependent claims

An encoding data processing apparatus operable to generate protected compression encoded data representative of protected media signals, the apparatus comprising:

a data analyser operable to receive compression encoded data representative of the media signals and to select low perceptibility data bits in the compression encoded data which when altered would have a relatively low perceivable effect on the media signals recovered from compression decoding the compression encoded data after the selected bits had been altered, the bits being selected in accordance with predetermined criteria,
an information validation engine operable
to form a normalised version of the compression encoded data by setting the selected data bits in the compression encoded data to a predetermined value,
to generate a secure hash value of the normalised version of the compression encoded data, and
to form the protected compression encoded data by replacing the selected data bits of the normalised compression encoded data with the data bits of the secure hash value.

2 more elements

A decoding data processing apparatus operable to validate protected media signals by decoding protected compression encoded data representative of the protected media signals, the protected compression encoded data containing validation data, the validation data having been calculated by identifying selected data bits in the compression encoded data in accordance with predetermined criteria which when altered would have a relatively low perceivable effect on the media signals, setting the selected data bits to a predetermined value to form a normalised version of the compression encoded data, calculating a secure hash value of the normalised version of the compression encoded data and replacing the selected data bits of the normalised version of the compression encoded data with the data bits of the secure hash value,

the apparatus comprising:
a data analyser operable to receive the protected compression encoded data and to identify selected data bits in the protected compression encoded data in accordance with the predetermined criteria,
an authentication engine operable
to extract the validation data from the selected bits,
to form a normalised version of the validated compression encoded data by setting the selected bits in the validated compression encoded data to a predetermined value,
to calculate a hash value of the normalised version of the validated compression encoded data, and
to compare the extracted validation data with the calculated hash value, the protected compression encoded data being verified as valid if the validation data and the calculated hash value match.

4 more elements

A decoding data processing method for validating protected media signals by decoding protected compression encoded data representative of the media signals, the compression encoded data containing validation data, the validation data having been calculated by identifying selected data bits in the compression encoded data in accordance with predetermined criteria which when altered would have a relatively low perceivable effect on the media signals, setting the selected data bits to a predetermined value to form a normalised version of the compression encoded data, calculating a secure hash value of the normalised version of the compression encoded data and replacing the selected data bits of the normalised version of the compression encoded data with the data bits of the secure hash value, the method comprising the steps of:

receiving the protected compression encoded data,
identifying selected data bits in the protected compression encoded data in accordance with the predetermined criteria,
extracting the validation data from the selected bits,
forming a normalised version of the protected compression encoded data by setting the selected bits in the protected compression encoded data to the predetermined value,
calculating a hash value of the normalised version of the protected compression encoded data, and
comparing the extracted validation data with the calculated hash value, the protected compression encoded data being verified as valid if the validation data and the calculated hash value match.

3 more elements

Dependencies are inferred from the claim text.

Data processing apparatus and method

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Data processing apparatus and method

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Abstract

Claims36