| The working and life style of people is influenced profoundly by the rapiddevelopment of computer technology. The appearance of peer-to-peer network changed thefile sharing style. The file transfer changed from traditional server transmit to peer nodedirect transfer. As the computing power of smart phone develops, people want to workmore quickly and efficiently by using mobile phones. The Android smart phones’development is the most rapid one. Although using smart phones for file transfer canfacilitate the information sharing, there are a lot of security problems. A file transferscheme is designed and implemented in this paper, by studying the security problem thatillegal users may steal files when an Android smart phone sharing them in LAN. In this filetransfer scheme, files can be transferred directly between the mobile phones via directrouting. It can avoid the security problem that illegal users steal files when the serverforwarding. The transmission is encrypted. It can reduce the possibility that illegal userssteal files when they are in transmission.The application design and development based on Android platform, common filetransfer protocol and data encryption techniques are studied in this paper. AES encryptionalgorithm and SSL security protocol are studied deeply for the implementation of the filesharing scheme. According to the characteristics of this file transfer scheme, AESencryption algorithm and SSL security protocol are conjunctively used to provide securityfor file transfer. The file transfer scheme is divided into two parts, mobile phone and server.The mobile phone is responsible for interacting with the user, file encryption anddecryption, and communication. The server is responsible for verifying mobile phones. Theencryption and decryption key is sent to these mobile phones which passed validation. Itcan ensure the safety of the key for file encryption and decryption.The file transfer scheme of the specific design process and implementation process areelaborated in detail in this paper. The detailed design is divided into four aspects includingarchitecture design, workflow design, communication design and security design. Thesystemic implementation is divided into two aspects. For the implementation ofcommunication, the short message realization and file transfer realization are implementedin detail. For the implementation of encryption, the SSL encryption and AES encryption aremainly implemented. The implementation of the file transfer scheme is tested practically at the end of the paper. Test results show that the file transfer scheme is feasible, and it hasachieved the target of file secure transmission, file encryption and decryption. |
