Abstract: Among other things, at a central server, management of a document sharing process includes uploading from client devices through a communication network, storing at the server, and downloading to client devices through the communication network documents that are shared between users of the client devices. Encryption keys are used to protect features of the documents from unauthorized or unintended disclosure. Operations are performed on encryption keys or encrypted data as a result of which protection of features of the documents from unauthorized or unintended disclosure may be compromised. A determination is made whether performance of a given one of the operations on any of the encryption keys or encrypted data meets predefined conditions for approval by members of an approval group. Performance of the operation on the encryption key or encrypted data is controlled based on a result of the determination.

Abstract: Among other things, at a central server, management of a document sharing process includes uploading from client devices through a communication network, storing at the server, and downloading to client devices through the communication network documents that are shared between users of the client devices. Encryption keys are used to protect features of the documents from unauthorized or unintended disclosure. Operations are performed on encryption keys or encrypted data as a result of which protection of features of the documents from unauthorized or unintended disclosure may be compromised. A determination is made whether performance of a given one of the operations on any of the encryption keys or encrypted data meets predefined conditions for approval by members of an approval group. Performance of the operation on the encryption key or encrypted data is controlled based on a result of the determination.