Description
Picture archiving and communication systems (PACS) are typical information systems, which may be undermined by unauthorized users who have illegal access to the systems. This article proposes a role-based access control framework comprising two main components – a content-based steganographic module and a reversible watermarking module, to protect mammograms on PACSs. Within this framework, the content-based steganographic module is to hide patients textual information into mammograms without changing the important details of the pictorial contents and to verify the authenticity and integrity of the mammograms. The reversible watermarking module, capable of masking the contents of mammograms, is for preventing unauthorized users from viewing the contents of the mammograms. The scheme is compatible with mammogram transmission and storage on PACSs. Our experiments have demonstrated that the content-based steganographic method and reversible watermarking technique can effectively protect mammograms at PACS.