Abstract: Protecting content is disclosed. A request for a file system operation is intercepted. A user-defined callback that corresponds to the file system operation is identified. The user-defined callback that secures the file system operation is executed. The user-defined callback may be used for pre or post-processing of data, authentication, and/or other use cases.

Abstract: A request to store a file to be protected is received. It is detected whether the file to be protected is a file to be synchronized. The encryption key is selected based on the detection of whether the file is a file to be synchronized. The file to be protected is encrypted using the selected encryption key.

Abstract: A request for a file system operation that has been intercepted at a remote second user system for a protected file is received. An indication to allow the file system operation is received. An instruction to allow access to the protected file by allowing the file system operation is provided to the remote second user system. While the remote second user system has the provided access authorization to the protected file, an indication to modify the access authorization is received from a user that allowed the file system operation. The remote second user system is instructed to implement the indicated access authorization modification.

Abstract: A request to store a file to be protected is received. It is detected whether the file to be protected is a file to be synchronized. The encryption key is selected based on the detection of whether the file is a file to be synchronized. The file to be protected is encrypted using the selected encryption key.

Abstract: A request to access a protected file is received. It is detected that an access key to the protected file is unavailable via a primary channel. Authentication with a mobile device is established. The access key is obtained from the mobile device. The access key is utilized to provide access to the protected file.