From Sealpath Technologies:
If you are worried because you share files very often and you want to avoid unauthorized accesses, SealPath is for you. With SealPath you can control who has access to your document and what they can do with it. If you need to be sure that somebody does not access a document any more, you can remotely delete it, even if the document is not in your hands. SealPath allows you to avoid the access of outsiders and to manage permissions.
SealPath is compatible with the habitual tools (Microsoft Office, Adobe Reader), which guarantees that you can still work as always. The installation of servers in the client and the download of viewers is not required, only registering on SealPath is needed. Besides, the documentation is not uploaded to any cloud, because it is protected on local. SealPath is based on AD RMS technology of Microsoft. With a simple drag and drop operation, you will be able to protect Office and PDF documents that you need to keep under control. SealPath uses a symmetric key with AES algorithm of encryption to ensure that your documents are under control. This symmetric key is obtained through a private RSA key that each user receives when he is authenticated on SealPath. Therefore, it is not necessary to use different passwords by document or user. Each user uses his password, which was chosen when registering on the platform, so as to access to the encrypted documents that he receives from other users or that were protected by him.
SealPath has been developed for workgroups, departments or companies that share documents with people outside the organization or outside their groups. You share whenever you want and you decide with whom, not people who receives the documents. With SealPath, when a user has downloaded your document to his PC, it does not mean that you lost the control of it. Wherever the document is, you are still the owner of it and you keep deciding what others can be done with it.