This is novel software integrating encryption technology with decryption technology. The features of this software can be concluded as follow: Based on the encryption engine of Microsoft, the software with mandatory encryption technology can be applied to all types of documents, and the encrypted document is stored in a special format. With the correct password, the encrypted document will be directly executed without decrypting as another file stored in the hard disk. Especially, execution of the encrypted document does not depend on this software. In other words, the encrypted document can be executed in the computers without the software installation. After execution, the encrypted document still remains in an encrypted state. The encrypted document even can set the number of executions. Once reaching the number, the encrypted document will be automatically deleted. It is an effective measure to ensure the document's security.