1. FromAudiobook to Multimedia-Book Zhoulan Zhang zzl@cs.pitt.edu http://www.cs.pitt.edu/~zzl/

2. 2 Audiobook The audio presentation of a written book  Initially used by sight-impaired people, slow learners  Allow “reading” while pursuing other activities  Children’s audiobook  In-car entertainment  Educational tools… Moving from conventional audiobook to digital audiobook (e-audiobook), offering different formats. e.g.MP3, WMA, AAC Multimedia Book(m-audiobook)

3. 3 Multimedia Book Adding images and text there are not included in e-audiobook e.g. Karaoke effect, CD/book cover, image, updated information Challenges  File size — bringing MMCs (Multimedia contents) may greatly increase the original file size  Compatibility — file structure may be modified  Synchronization — synchronize text and image with audio content  Security — ensures perfect audio quality and full access to MMCs only to legal users

4. 4 Outline Introduction Adding multimedia contents (MMC) to e- audiobook  factors to consider: size, compatibility, synchronization Security System  from the views of vendor, and user Distribution Architecture  who will be involved? procedures? Reviews and Conclusions

5. 5 E-audiobook Format Due to copyright and security problems, images and text are not provided with e-audiobooks. Format is questioned Some try to impose proprietary formats coupled with DRM(Digital Rights Management). e.g. Apple DRM MP3  Familiarity with the format  The large quantity of audio now available in MP3  The lack of DRM restrictions, which makes MP3 files easy to edit, copy and distributed over networks Making audiobook applications more attractive! Taking advantage of current mobile and multimedia scenario… How to add MMCs to MP3 e-audiobook?

6. 6 Incorporating Multimedia Content (MMC) MMCs include: CD/book cover, image, karaoke-like service, updated information Goal1: without changing MP3’s file structure Goal2: minimize incrementing of MP3 file size Goal3: synchronization— timing property

7. 7 Incorporating MMC Goal1: without changing MP3’s file structure

8. 8 Incorporating MMC Goal1: without changing MP3’s file structure Describe all MMCs via a multimedia description language And store the resulting description into the MP3 files (Id3V2)

9. 9 MECDL MECDL (MP3 Enhanced Contents Description Language) Designed to allow the spatial layout of different media elements to be described as well as temporal order in which these elements will play during presentation; Similar to makeup languages like SMIL and MPEG-7 DDl; however, it produces shorter MMCs description.

10. 10 An Example of an MECDL description

11. 11 MECDL Tags and Attributes

12. 12 Incorporating MMC Goal2: minimize incrementing of MP3 file size MECDL does not store image directly into the e- audiobook. Only a link is stored. External media can be linked to MP3 file, but still live independently, for greater flexibility. MMC should be inserted into the MP3 file only on user request. The user need not to pay, in terms of downloading time and costs, for MMCs in which he/she is not interested.

13. 13 Incorporating MMC Goal3: synchronization— timing property Timing information that relates the written text to the audio file is stored directly. The attribute time allows to establish timing relation between the text and the audio All the timing relations are represented by time units, defined via the unit value(in milliseconds) – granularity

14. 14 An Example of an MECDL description

15. 15 Outline Introduction Adding multimedia contents (MMC) to e- audiobook  factors to consider: size, compatibility, synchronization Security System  from the views of vendor, and user Distribution Architecture  who will be involved? procedures?

16. 16 Security Goals Goal(1) Protecting the rights of the source, allowing playout of an m-audiobook to only those who legally bought it Goal(2) Protecting both source and user from unauthorized alteration of the MMCs. Goal(3) Giving the content provider the possibility of tracing the distributors of illegal copies Goal(4) Providing transparency to honest users and allowing them fair use of the m-audiobook Techniques: encryption, digital signature, watermarking

17. 17 Security System The source endows each user with a proprietary player Each player is provided with a specific watermarking key. Only the player that uses that key can retrieve the watermarked data. WID=H(MMC1 || H(E k (MMC2))) for the weak inte veri K-- the symmetric key for decrypting E k (MMC2) α-- the symmetric key for decrypting the audio stream F-- a fingerprint for traitor tracing

18. 18 Security Goal 1 Allow unprotected reproduction of first portion(30s) of the audio stream Second portion play-out needs αand K Give the software player sufficient time to retrieve the decryption key without imposing any delay on the user  Goal1 is met (protecting the rights of the source, allowing playout of an m-audiobook to only those who legally bought it)

19. 19 Security Goal 2 For consumer protection, there is a verification procedure that inhibits playout if MMCs have been altered: WID=H(MMC1 || H(E k (MMC2))) For forensic purposes, in a website maintained by a music distributor, the signiture σ= Sig(PH(audio)||MMC1||MMC2) is made available  Goal 2 is met (protecting both source and user from unauthorized alteration of the MMCs)

20. 20 Security Goal 3 Traitor Tracing: a Trusted Third Party(TTP) embeds a fingerprint in the second portion of the audio stream. The fingerprint data can be watermarked in the audio stream only before encryption. Even if a user makes “personal” copy of the audio stream, the copy is marked with the unique fingerprint of the user. Goal 3 is met (giving the content provider the possibility of tracing the distributors of illegal copies)

21. 21 Security Goal 4 To ensure fair use policy, the player should provide the user with the ability to burn personal copies of the m-audiobook Only audio not MMC Goal 4 is met (providing transparency to honest users and allowing them fair use of the m- audiobook)

22. 22 Outline Introduction Adding multimedia contents (MMC) to e- audiobook  factors to consider: size, compatibility, synchronization Security System  from the views of vendor, and user Distribution Architecture  who will be involved? procedures?

23. 23 Distribution Architecture Three different entities with different tasks participate in the realization of an m-audiobook M-audiobook production is done by the source and the TTP( trusted third party) M-audiobook distribution is done by the interactions among the customer, the source, and the TTP M-audiobook playout is performed at the customer side by a special player

24. 24 Distribution (1)C requests an m- audiobook for S, disclosing the ID of his software player (2) S gives C the data necessary to complete payment and requests that C contact TTP for payment; (3) C contacts TTP, transfers to TTP all necessary data, and payment is completed

25. 25 Distribution (4) TTP informs S that C has paid; (5) S embeds WID, K, and α in the audio stream using the player’s watermarking key, adds the MMC’s description to the ID3v2 field and forwards the audio stream to the TTP for fingerprint insertion along with the encryption key α; (6) TTP embeds a fingerprint F in the portion of the audio stream following the first 30 seconds worth, and encrypts that portion with the key α. F identifies C uniquely; TTP forwards the resulting m-audiobook to C and informs S that the transaction has been completed.

26. 26 Reviews The security mechanism proposed above imposes symmetric decryption of audio and textual data on the end devices; however, complex computation may not be suitable for some portable devices. Watermarking assumptions. Assume that the WM is invisible, robust, and tamper-resistant. Secure hash function assumptions Other formats (AAC) In the proposed distribution architecture, customer may communicate with source directly

27. 27 Conclusion MECDL efficiently enriches MP3 files with MMCs MP3 file is no longer a single audio track, but a media-rich product The security mechanism protects both the vendor and consumer May find new markets for audiobook industry in educational and entertainment worlds

28. 28 Reference [1] L Egidi and M Furini, “From Digital Audiobook to SecureDigital Multimedia-Book”, ACM Computers in Entertainment, Vol.4, No.3, July 2006 [2] L Egidi and M Furini, “Bringing Multimedia Contents into MP3 Files”, IEEE Communications Magazine, May 2005 [3] Watermarking world, http://watermarkingworld.org/faq.htmlhttp://watermarkingworld.org/faq.html [4] Digital Rights Management from Wikipedia, http://en.wikipedia.org/wiki/Digitial_Rights_Management http://en.wikipedia.org/wiki/Digitial_Rights_Management [5] Windows Media DRM FAQ, http://www.microsoft.com/windows/windowsmedia/forpros/drm/fa q.aspx http://www.microsoft.com/windows/windowsmedia/forpros/drm/fa q.aspx [6] iPod Q&A http://www.everymac.com/systems/apple/consumer_electronics/i pod_faq/ipod-supported-music-formats-good-sound-quality.html http://www.everymac.com/systems/apple/consumer_electronics/i pod_faq/ipod-supported-music-formats-good-sound-quality.html