At present, most of the computer systems are integrated into a network. The purpose of integrating a computer system into a network is to make system more effective and easy to access. In this integrated system, most of the data and information are stored in a file at a server. On the other hand, the information, data and file stored in the server has a potential to be threatened by intruders.. Pretty Good Privacy (PGP) concept is related with the issue of computer security and was used for electronic mail. In this study, the concept of PGP was apply to enhance the security level for a digital file. This paper describes the concept of PGP and explains the methodology used to implement a security program. The changes of the digital file content for each process including cryptography and compression were presented as the results of this study.