The consolidation of health information has led to the creation of a national network of medical institutions. In this wireless and hard-line communication web, patients' medical information, which is extremely private and must be kept in secret, may leak out, and the risk of dangers such as privacy infringement and misuse of information has increased.

For this dissertation, a patient information protection algorithm was designed for a hospital information system in order to improve the untraceability and anonymity of patients' individual information in a ubiquitous computing environment.

Additionally, analyzing the computing load showed that the computing load of the entire system did not increase, and since 57 percent of the sensor node's computing load was transferred to the secure server, the sensor node's load was minimized. Thus, the system can also be applied to low performance sensor networks.

In conclusion, improving the security level of identification information transmissions while minimizing the computing and communication load of sensor nodes in a ubiquitous computing environment did not lead to an increase in the system's overall computing or communication load. Thus, a system with improved security features for identification information and communication information was developed and established.