Abstract: An embodiment of the present invention discloses a data protection method in which it is checked whether a data receiving party has a valid digital license generated by the data transmitting party, at a time when the data receiving party is to decrypt the encrypted data from a data transmitting party. If so, the data receiving party is permitted to use at least one key required in the data decryption process. Also disclosed in the embodiment of the present invention is a data protection system. The embodiments of the invention realize secure usage of shared data in cloud office era.

Abstract: The present invention provides a method for certifying an Android client application by a local service program. In the method, a client application is signed to generate a certification information file; when the client application is run in an Android system, the certification information file is certified by a local service program, and the client application can normally use services provided by the local service program as long as the certification is successful. By the method provided by the present invention, a tampered client application is unable to acquire functions of a local service program, so that legitimate software is distinguished from malicious software, and the security of both the Android system and the network is ensured.