A Safe Disk In Windows Environment

Cryptography is an important technology to ensure data security, and has been widely utilized to transfer and store information. Cryptography based on file encryption and disk encryption is usually used to protect data stored inside computers. The first method is to encrypt a file or all files under a certain directory chosen by the user, while the second one encrypts all sectors on the entire disk.However, both of these methods give an adversary too much information. Namely, it is obvious to prying eyes that there is some sensitive data in the user's computer. This fact may make the enemy suspicious enough that he tries other methods of recovering the data.To resolve this problem, this paper uses technology of information hiding to implement a virtual disk device driver, and the encrypted data is hidden into some files so that it is difficult to be found out. Each secure volume is corresponding to a series of digital image files and assigned a drive letter. When the secure volume is mounted, the user must input correct password as authentication ID. The security is implemented in a two-step process. First, the driver use AES algorithm to encrypt the data being written to the drive, and the encryption key is generated by hashing the user's password with the SHA-1 hashing algorithm. Second, it hides the encrypted data in a series of digital image files. Therefore, an attacker viewing the system would not be aware that any sensitive data exists on the machine, and this ensures the secret and the protection scale of the data.