Adobe LiveCycle Rights Management is a server-based security system that provides dynamic control over PDFs. It is a complex solution which, besides PDF, supports many document formats e.g. Microsoft Word.
Its key capabilities, according to their website, are
- Restrict access of a document to certain individuals only.
- Monitor the usage of a given document.
- And most notably, revise usage rights or revoke access to documents after they have been distributed.
All of these dynamic capabilities require some kind of server based solution; the usage rights and the access policy is, instead of being part of the document, provided by some external policy server
In practice, that requires the clients (e.g. a PDF viewer application) and the policy servers to implement a communication protocol to obtain decryption keys, access policy and so on. Obviously, Adobe has the technology for a relatively safe communication between the client and the policy servers. However, it is not public technology, third party software cannot implement it.
If you encounter the exception "Unsupported encryption found" in any of TallComponent's PDF components, it is very likely that you stumbled upon a PDF treated with this DRM. All you can do is to double check whether this is the case. To check it, open your document with Adobe Reader (it might take some time as it has to connect the policy server to check the access restrictions). Open Security Settings, then select Permission Details:
The Security Method field contains the applied encryption algorithm. If it says "Adobe LiveCycle Rights Management", you are unfortunately bounded to Adobe Reader.