Re: [freenet-support] Remove all identifying content from posted files (especially audio)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Brian Mearns wrote: On Thu, Sep 10, 2009 at 6:54 AM, SmallSister development smallsis...@xs4all.nl wrote: Brian Mearns wrote: I understand the basic architecture of Freenet and how it protects contributors, but I'm concerned that the files themselves might contain identifying information about the source of the file. In particular, for audio files such as MP3, Ogg Vorbis, and Flac. Does anyone have any information on making sure there are no fingerprints left on these files when posting? There is no way to be certain. There could be a future algorithm piecing together just enough bits from a file to identify you. Word frequency analysis has been used to discern likely writers of a plain text file. Yes, you can avoid stupid mistakes by checking for known signatures and removing them, but that is something that would be different for different file types (ogg would be somewhat different from mp3; but doc and pdf require totally different approaches.) It would be useful to have tools that can identify and remove watermarks and Freenet would be a great place to publish them (with source code please!) Peter. ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe Bugger, I didn't even think of steganographic watermarks (shame on me), I was thinking more in terms of meta data known to be stored with various file formats (like ID3 tags), but this seems to be more complicated than I expected. Thanks for the insight. -Brian For audio and video the best approach could be to take the streams and remux them into the same container type, then to copy only the metadata which the user knows about (for example some audio files have autogain settings, etc). You would still have a potential for watermarking, as Peter already pointed out, and these watermarks will become more and more common as Internet Music Shop software develops (this is not to assume that internet shops is the only source of watermarked audio, other groups can watermark a file, this is most dangerous in countries where freenet is illegal(*)). - Volodya (*) An agent of the state can insert a completely legal file that one believes would be downloaded and not hidden by average freenet user, let's say it is a public domain humorous poem. Even those users who are completely paranoid and run Freenet on a hidden encrypted partition may let their guard down and copy said file outside of encrypted partition, or post it on their blog. This, however, can be used to identify them as Freenet users, if the version of the file distributed on Freenet has been watermarked. - -- http://freedom.libsyn.com/ Echo of Freedom, Radical Podcast http://www.freedomporn.org/Freedom Porn, anarchist and activist smut None of us are free until all of us are free.~ Mihail Bakunin -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkqsmd8ACgkQuWy2EFICg+1MxACdGDNX7UcUzs5yl+S6HTBGNWGR K/AAoMYWgT+HkKgxZUrxTMIGBJBZxfP1 =JOVB -END PGP SIGNATURE- ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe
Re: [freenet-support] Remove all identifying content from posted files (especially audio)
VolodyA! V Anarhist wrote: Brian Mearns wrote: On Thu, Sep 10, 2009 at 6:54 AM, SmallSister development smallsis...@xs4all.nl wrote: Brian Mearns wrote: I understand the basic architecture of Freenet and how it protects contributors, but I'm concerned that the files themselves might contain identifying information about the source of the file. In particular, for audio files such as MP3, Ogg Vorbis, and Flac. Does anyone have any information on making sure there are no fingerprints left on these files when posting? There is no way to be certain. There could be a future algorithm piecing together just enough bits from a file to identify you. Word frequency analysis has been used to discern likely writers of a plain text file. Yes, you can avoid stupid mistakes by checking for known signatures and removing them, but that is something that would be different for different file types (ogg would be somewhat different from mp3; but doc and pdf require totally different approaches.) It would be useful to have tools that can identify and remove watermarks and Freenet would be a great place to publish them (with source code please!) Bugger, I didn't even think of steganographic watermarks (shame on me), I was thinking more in terms of meta data known to be stored with various file formats (like ID3 tags), but this seems to be more complicated than I expected. Thanks for the insight. For audio and video the best approach could be to take the streams and remux them into the same container type, then to copy only the metadata which the user knows about (for example some audio files have autogain settings, etc). You would still have a potential for watermarking, as Peter already pointed out, and these watermarks will become more and more common as Internet Music Shop software develops (this is not to assume that internet shops is the only source of watermarked audio, other groups can watermark a file, this is most dangerous in countries where freenet is illegal(*)). I have heard noticed that multiple rips of the same CD can produce different .wav files; some of the differences are caused by the CD-player firmware and some caused by scratches/defects on the CD. Add some compression artefacts of the mp3 encoder (subtle algorithm differences between implementations) and you're very likely able to identify each mp3 uniquely. Even re-encoding may be detectable. NOTE: this is all without explicitly inserting a watermark. Remuxing and detection and removal of steganographic watermarks is likely to bring you 95% of the way; which could be good enough. ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe
Re: [freenet-support] Remove all identifying content from posted files (especially audio)
I'd love to know about this too! I understand the basic architecture of Freenet and how it protects contributors, but I'm concerned that the files themselves might contain identifying information about the source of the file. In particular, for audio files such as MP3, Ogg Vorbis, and Flac. Does anyone have any information on making sure there are no fingerprints left on these files when posting? Thanks, -Brian -- Feel free to contact me using PGP Encryption: Key Id: 0x3AA70848 Available from: http://keys.gnupg.net ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe
Re: [freenet-support] Remove all identifying content from posted files (especially audio)
... especially in pdf and doc files ... I understand the basic architecture of Freenet and how it protects contributors, but I'm concerned that the files themselves might contain identifying information about the source of the file. In particular, for audio files such as MP3, Ogg Vorbis, and Flac. Does anyone have any information on making sure there are no fingerprints left on these files when posting? Thanks, -Brian -- Feel free to contact me using PGP Encryption: Key Id: 0x3AA70848 Available from: http://keys.gnupg.net ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe
Re: [freenet-support] Remove all identifying content from posted files (especially audio)
Brian Mearns wrote: I understand the basic architecture of Freenet and how it protects contributors, but I'm concerned that the files themselves might contain identifying information about the source of the file. In particular, for audio files such as MP3, Ogg Vorbis, and Flac. Does anyone have any information on making sure there are no fingerprints left on these files when posting? There is no way to be certain. There could be a future algorithm piecing together just enough bits from a file to identify you. Word frequency analysis has been used to discern likely writers of a plain text file. Yes, you can avoid stupid mistakes by checking for known signatures and removing them, but that is something that would be different for different file types (ogg would be somewhat different from mp3; but doc and pdf require totally different approaches.) It would be useful to have tools that can identify and remove watermarks and Freenet would be a great place to publish them (with source code please!) Peter. ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe
Re: [freenet-support] Remove all identifying content from posted files (especially audio)
On Thu, Sep 10, 2009 at 6:54 AM, SmallSister development smallsis...@xs4all.nl wrote: Brian Mearns wrote: I understand the basic architecture of Freenet and how it protects contributors, but I'm concerned that the files themselves might contain identifying information about the source of the file. In particular, for audio files such as MP3, Ogg Vorbis, and Flac. Does anyone have any information on making sure there are no fingerprints left on these files when posting? There is no way to be certain. There could be a future algorithm piecing together just enough bits from a file to identify you. Word frequency analysis has been used to discern likely writers of a plain text file. Yes, you can avoid stupid mistakes by checking for known signatures and removing them, but that is something that would be different for different file types (ogg would be somewhat different from mp3; but doc and pdf require totally different approaches.) It would be useful to have tools that can identify and remove watermarks and Freenet would be a great place to publish them (with source code please!) Peter. ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe Bugger, I didn't even think of steganographic watermarks (shame on me), I was thinking more in terms of meta data known to be stored with various file formats (like ID3 tags), but this seems to be more complicated than I expected. Thanks for the insight. -Brian -- Feel free to contact me using PGP Encryption: Key Id: 0x3AA70848 Available from: http://keys.gnupg.net ___ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe
