SECURE ENCRYPTION FOR CONFIDENTIAL INFORMATION

摘要

This paper describes a method for safe encryption of confidential information travelling through personal computer's memory. Personal details such as user credentials, credit card numbers, emails are usually either typed in from the keyboard or accessed to be read on the monitor. Our proposed method uses an external encryption device interconnected between computer's main unit on one side and keyboard and monitor on the other side. This design physically insolates this protection process from unauthorized access threats, usually lying inside computer's internal memory. Clear-text information typed from the keyboard is encrypted before entering the computer. Secured information coming to be displayed is decrypted and displayed in clear-text form on the monitor. Security of the encrypted information is ensured by the AES (Advanced Encryption Standard) algorithm used in combination with 128-bit keys, kept on a smartcard. A separate communication channel between the device and the computer assures the transfer of encrypted data in both directions. When no encryption is necessary, the device acts transparently, simply forwarding the information. When protection is required, the encryption/decryptuion process transforms the information and redirects/gets secure content to/from the special communication channel. In the following sections describe the system architecture, design and implementation and in the end some conclusions and possible improvements of the proposed system.