Hi, are there any open source DRM implementations for protecting Theora streams over RTP? I only know of the ISMACryp specification which seems to be licence free and so could be used in an open source project. Regards, Franz
fboehm <fboehm at aon.at> wrote ..> Hi, > > are there any open source DRM implementations for protecting Theora > streams over RTP?Please reconsider. Digital Restrictions Management is wrong for lots of reasons. http://www.fsf.org/campaigns/drm.html
On Tue, May 25, 2010 at 9:41 AM, fboehm <fboehm at aon.at> wrote:> Hi, > > are there any open source DRM implementations for protecting Theora > streams over RTP?Jason-- I don't think he means 'DRM' exactly. I think he's more interested in a private encrypted stream. Franz-- We don't generally track DRM, as it's usually used to try to control download and that application is demonstrably impossible. It can only work for as long as the control mechanism remains obfuscated, and open source naturally lays all mechanisms bare for ispection. Athentication, privacy and watermarking are obviously all possible though... perhaps you should clarify what you're trying to do? Monty
fboehm wrote:> Hi, > > are there any open source DRM implementations for protecting Theora > streams over RTP? > > I only know of the ISMACryp specification which seems to be licence free > and so could be used in an open source project. > >To wrap theora in RTP, you need to follow the internet draft, which you can find at http://tools.ietf.org/html/draft-barbato-avt-rtp-theora-01 . This is a draft, and has som gotchas. I recently implemented this in a proprietary video conferencing system, and can share some of the stuff I found out by doing that. I send the RTP in plaintext myself, but for encrypting RTP streams you have SRTP in addition to the ISMACryp. I don't know whether ISMACryp is adapted to theora or need adaption in the first place. SRTP encrypts the entire RTP payload, so it can be applied without codec-specific adaptations. It is defined in rfc 3711, available at the following URL. http://www.ietf.org/rfc/rfc3711.txt When it comes to DRM, you are on your own. To my knowledge nobody has made any DRM system for theora. Given that theora is an open codec, developing a DRM scheme runs counter to the goal of the project. Those who spend time and effort to develop a free codec, will probably not think that developing a DRM scheme is a project worth spending their limited time on, and those interested in cryptography know that DRM theoretically cannot be more than security by obscurity, and is therefore not interested. Nothing (legally or otherwise) stops you from developing DRM for theora. You may be able to use or adapt ISMACryp, but you are likely be the first to do that, and very likely also the first to implement DRM for a theora stream over RTP. Not many people have implemented theora over RTP at all, and all I know about transfer the streams in plaintext. -Gisle
--- On Wed, 26/5/10, Gisle S?lensminde <gisle at snirklasjon.no> wrote:> From: Gisle S?lensminde <gisle at snirklasjon.no> > Subject: Re: [theora] DRM for Theora over RTP > To: "fboehm" <fboehm at aon.at> > Cc: > Received: Wednesday, 26 May, 2010, 8:55 AM > fboehm wrote: > > Hi, > > > > are there any open source DRM implementations for > protecting Theora > > streams over RTP? > > > > I only know of the ISMACryp specification which seems > to be licence free > > and so could be used in an open source project.Depending on your bandwith needs you could cryptographic hash function[1] [1] http://en.wikipedia.org/wiki/Cryptographic_hash_function tom sparks