中文摘要：

数字音视频编码器在数字电视系统中占有核心地位，对其进行软件保护具有非常重要的现实意义。在对数字电视系统整体结构进行分析的基础上，深入研究了数字电视中编码器软件的加密技术。针对现有编码器中加密方法的不足，提出了一种基于硬件信息的软加密技术，以具有唯一性的多项硬件信息为加密依据，采用MD5算法对获得的信息进行加密，充分考虑了编码器“一机一码”的需求，从而可以有效防止非法注册。此外，系统合理地选择了非对称RSA算法来防止非法注册的生成，对编码器软件进行加密保护。测试表明，该方法加密及破解强度均很高，能够很好地完成编码器软件加密要求，从而可以有效地保护编码器软件发行商的合法权益。

英文摘要：

Digital audio and video encoder plays a key role in the system of the digital television. It is very important that the software protection is processed for the encoder. Force on the analyses of digital television system, the encryption techniques for video encoder have been studied intensively. According to the shortages of the current encryption techniques, a method of soft eneryption based upon the information of hardware is proposed. Based on some unique hardware information, the algorithm of MD5 is adopted to encrypt the obtained information, It can avoid the illegal registration because it meets the requirements of one-machine-one-code well, The experiment shows that the method which has high intensity of encryption and cracking can satisfy the eneryption requirement of eneoder soft. It can nicely protect the legitimate rights of software publishers.