I have a client who is a publisher and also runs an on-line book store. They are looking into selling eBooks that have DRM licenses. When a user buys the book they are able to download it and then activate the license. The license is activated for that device and the eBook is then locked to that device.
What sort of software exists to handle this process (just the DRM and licensing activation)?
Are there any cheap option (unfortunately DRM free is not an option)?
Adobe has a bunch of rights management tools for encrypted PDFs. These can also be integrated into a Flash/Flex application that could provide the locking you desire.
Mobi allows for DRM as well (and have great tools for producing it) http://www.mobipocket.com/en/DownloadSoft/default.asp?Language=EN
AFAIK there isn't an easy solution for locking content to a single device.
Generally, if you want to lock a piece of content to a device, you need some cooperation from the device firmware. The Nook and the Kindle have this capability I believe, but you'll need to use their protections schemes to take advantage of it. I'm not sure about other devices.
OMA drm for content protection defines protocol for machine binding. Also you can implement your own drm solution but problem will be how will the reader bind with your application? In that case you need to come up with the reader integrated solution. I hope you get the point.