Research And Implement Of File Transparent Encryption Technology Based On Android

The rapid progress of mobile Internet as well the fast rising of smart phone isproviding people with a fresh experience of life. People are enjoying this new experiencewhile they are also encountered with an increasingly serious problem of mobile datasecurity. There are already many kinds of encryption applications to protect files andinformation in cellphones in market nowadays. However, most of these applications areencrypted in user mode. They need users to input password through authorization wheneverthey intend to use a file, which is low in encryption efficiency and user experience.After the study of Android and transparent encryption technology, a file transparentencryption application based on Android was designed and implemented. Hook transparentencryption technology as well as AES encryption algorithm is applied to this application,which make it possible for this application to protect files in cellphones safely andeffectively. It consists of four modules as follows: Encryption Strategy Customization,Read/Write Monitoring, Encryption/Decryption and Data Read/Write, among whichEncryption/Decryption is the most important.Designed application can run on Android, which has been the most populardeveloping platform for developers with its strength in being complete, open, and free. Inaddition, Hook technology is used to achieve transparent encryption. Different fromtraditional encryption applications it shifts authentication to smart phone’s starting up. Thus,users can use a file repeatedly without inputting password after the first authentication,during which users can hardly notice encryption or decryption. In fact, encrypted files inthe cellphones are well protected and can only be read in users’ own cellphone, anyone whotries to copy or move them into other devices, or tries to read them through PC would fail.Finally, in order to ensure the stability and compatibility of the application, each levelof testing from unit testing to system testing is performed after coding. Testing results showthat application achieved can protect the files on a smart phone effectively, successfullyapplying transparent encryption and AES to mobile platform. At the same time, it canoperate stably and safely with comparatively low resource consumption.