With the trend of BYOD (Bring Your Own Device), i.e., using personal mobile devices for work, proliferating, one can easily find people doing their work anytime, anywhere. BYOD has the benefits of reducing business expense and increasing work productivity and efficiency. Nonetheless, the uncontrolled access of internal networks by the personal devices, for which enterprises have limitations in controlling, exposes the companies to security threats such as leak of confidential data and access by unauthorized users, yet there are inadequate countermeasures. Therefore, there is a need for a means of collecting the personalized context data of the user accessing the internal network and detecting and controlling abnormal user access by establishing a context-based policy. This paper presents measures for detecting abnormal access by collecting the context data according to the various devices and access environment and establishing the context data-based policy under the BYOD environment.

The term BYOD(Bring Your Own Device) collectively refers to the related technologies, concepts and policies, where employees do works by accessing corporate's IT resources, such as database and applications, using their personal mobile devices like smart phones, laptop computers and tablet PCs. However, with this trend serious security issues are emerging as a diversity of personal devices with unreliable security are increasingly accessing the typically closed intranets of conventional work environments. Corporations want to improve their productivity by taking advantage of the benefits of BYOD but it is difficult to handle an open BYOD work environment with current security technologies. As the access control policy of the NAC and MDM system is uniformly applied to users, however, they cannot be aggressive in implementing BYOD since there are security threats due to the frequent loss and theft of devices and low security. Accordingly, it is necessary to be able to flexibly set up policies and detect and control abnormal users by collecting personalized context information. In This study analyzes the BYOD environments, current threats to security and required security technologies, and presents a security framework for BYOD environments.