一种基于对称加密和隐写术的反取证方法

提出了一种结合使用对称加密和隐写术的反取证方法。该方法用对称加密和异或运算对文件进行隐秘处理，较好地缓解了传统对称加密中短密钥便于记忆和长密钥更加安全之间的矛盾。在对称密钥泄露的情况下仍能保证隐秘文件的安全。该方法用低开销大幅度提高了破解难度，对隐写的载体文件没有特殊要求，适合在反取证环境中使用。根据此方法，开发了基于Windows平台的反取证原型工具Steg Encrypt，该命令行工具可用于使保存或传送的文件难以暴力破解。

An Anti-forensic Scheme Based on Symmetrical Encryption and Steganography

In this paper, a anti-forensic scheme based on symmetrical encryption and steganography is proposed. According to the scheme, the secret file is processed by the algorithm of symmetrical encryption and XOR, and it can not be reconstructed by the attacker even the symmetrical key is revealed. The contradiction between convenience of short key and security of long key, which exists in traditional symmetrical eneryption, is mitigated by the scheme. The difficulty of cracking is notably augmented with a low cost and there is no special requirement on the carrier files using in steganography. So the scheme is suitable for the application environment of anti-forensic. On the basis of the scheme, a prototype tool, which is called StegEncrypt, is developed in Windows platform. This command-line tool can be used to make it hard to decrypt the files, which are to be saved or transferred, by force.