Privacy for MHEALTH Presence

mHealth data provision focuses on providing health services to patients via mobile devices and presence technologies. It has great influence to the healthcare business today, especially in the developing countries. However, the mHealth presence might be sensitive; and it brings potential privacy issues. For controlling what presence information can be given to which watcher, and when in mHealth presence service, XML Configuration Access Protocol (XCAP) is introduced. Nevertheless, it is not enough if only XCAP is applied. It just controls the direct privacy leakage; indirect flow might still leak the privacy information. Thus, presence authorization policy and privacy filter, which are components of XCAP, areimproved based on k-anonymity for stopping indirect privacy leakage.