A Modified Location-Dependent Image Encryption for Mobile Information System

The wide spread use of WLAN (Wireless LAN) and the popularity of mobile devices increases the frequency of data transmission among mobile users. In such scenario, a need for Secure Communication arises. Secure communication is possible through encryption of data. A lot of encryption techniques have evolved over time. However, most of the data encryption techniques are location-independent. Data encrypted with such techniques can be decrypted anywhere. The encryption technology cannot restrict the location of data decryption. GPS-based encryption (or geoencryption) is an innovative technique that uses GPS-technology to encode location information into the encryption keys to provide location based security. In this paper a location-dependent approach is proposed for mobile information system. The mobile client transmits a target latitude/longitude coordinate and an LDEA key is obtained for data encryption to information server. The client can only decrypt the ciphertext when the coordinate acquired form GPS receiver matches with the target coordinate. For improved security, a random key (R-key) is incorporated in addition to the LDEA key. The proposed method is applied for images.