Digital rights management Audio watermark Jiamian

Outline Definition Mechanism Properties Application Case discussion

1.definition What is audio watermark?

1.definition Watermark a.origin: paper manufacture b.definition:an identification code embedded in an electronic document that is used to identify the ownership or authenticate a document c.type:image watermark audio watermark video watermark

1.definition Audio watermark A watermark embedded within an audio stream to identify its origination The record industry is losing money!

Outline Definition Mechanism –coming topic Properties Application Case discussion

2.mechanism How does it work?

2.mechanism-main idea

2.mechanism Bitstream Watermarking

Outline Definition Mechanism Properties-coming topic Application Case discussion

3.properties What requirements should be met?

3.properties Efficient Computation: There should be low computational complexity for watermark embedding and extraction No Distortion of Original Signal and no format change Robustness:the ability to detect the watermark after common signal processing operations and hostile attacks Imperceptibility:the watermark should not be noticeable

Different attacks Signal diminishment attack Collusion attack Invertibility attack

Different attack Signal diminishment attack:the removal of a watermark by performing operations of audio signal(conversion,lossy compression, modulation, time stretch)

Different attacks Collusion attack:have copies of multiple works that have been embedded with the same watermark.By averaging the sample values of audio signal, one could estimate the value of the embedded mark,and then subtract it Sample:around 10 Countermeasure: embed more than one watermark make watermarks dependant on the characteristics of audio file itself

Different attacks Invertibility attack:it is possible to embed multiple marks on a single audio file.If Alice has the original file A,Bob ha a counterfeit original B derived from A,then Alice can find her watermark in Bob‘s file but the converse will not happen An attack to this procedure can be created.

3.properties Efficient Computation: There should be low computational complexity for watermark embedding and extraction No Distortion of Original Signal and no format change Robustness:the ability to detect the watermark after common signal processing operations and hostile attacks Imperceptibility:the watermark should not be noticeable

3.property-imperceptibility similarity between the original and watermarked version Original versionWatermarked version

3.property-imperceptibility Almost no difference!

outline Definition Mechanism Properties Application-coming topic Case discussion

4.Application How do we use it?

4.Application Proof of Ownership Access Control Tracing Illegal Copies

4.Application- Proof of Ownership Embedding of Copyright. InformationDuring production, copyright information in the form of a watermark can be anchored directly in the recording.

4.Application- Access Control embed a watermark that is used as a trigger

4.Application- Tracing Illegal Copies Embedding of Recipient Information.Personalize every recording distributed. In such cases information is embedded as a watermark that can be used at a later time to monitor recipients. This can be the recipient's customer number, for example. If these recordings are found later on the Internet, the embedded data can be used to identify the person to whom the recorded material was originally distributed.

Outline Definition Mechanism Properties Application Case study

5.Case study the audio watermarking technology utilized were developed at the Fraunhofer Institute for Integrated Circuits IIS in ErlangenFraunhofer Institute for Integrated Circuits IIS

5.Case study-business module Watermark Embedding: MusicTrace offers software products for embedding digital watermarks into audio signals. By means of these products it is possible to transmit additional information, e.g. a transaction number, hidden in the music. Internet Search: After receiving an order from a customer, MusicTrace searches in websites for music titles or audio books with embedded watermarks using its Internet tracing system. Using this information, the customer can identify the original recipient and, if necessary, take legal action

Business module-watermark embedding ContentMarkPCM: ContentMarkPCM permits embedding of watermarks in uncompressed audio signals. These can either be PCM files or WAVE files. The result of processing is still uncompressed audio files that are provided with watermarks.

Business module-watermark embedding ContentMarkCD: With the aid of ContentMarkCD it is possible to make any desired number of copies of an audio CD, each bearing a different watermark. These audio CDs sound identical to the human ear, however are discernable on the basis of the watermark.

Business module-watermark embedding ContentMarkMP3: ContentMarkMP3 is a product for embedding watermarks in existing MP3 audio files. The format is not changed by the watermark, consequently the MP3 audio file still conforms with standards. After watermarking, the file can be played on any MP3 player and is accepted by any MP3 player software that also accepts the original MP3 file.

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