According to DICOM standard Part 15 Security Profiles, the security issues of the medical informatics in the clinical environment and the techniques to implement this standard in a DICOM C++ library have been investigated. Three topics are included in this research: (1) implementing the security profiles standard in the DICOM C++ library that used in the image manager system; (2) upgrading the DICOM library that dealing with DICOM object coding, decoding, and network data transfer; and (3) adding the security network communication capability and encryption ability to authenticate the DICOM image objects.