DVB CSA的选择密文攻击原理及其实现

介绍了一种针对DVB-CSA(DVB标准加解扰算法)的选择密文攻击方案,其中包含了密钥搜索、压缩存储、硬件加速、安全芯片攻击等技术,基于这些技术永新视博公司研发出了一套DVB-CSA解密机演示系统。该演示系统由安全芯片终端机顶盒和一台解密机组成,能够在一定时间(相当于1个CP周期)内解密出CW(密钥)并扩散给其他终端机顶盒供其收看加密节目,在效果上达到只要能够获取到加密码流中一个指定密文TS包的对应明文,便可解密出CW并扩散。该方案的实现说明现在使用的DVB-CSA算法已经过时,即使是在安全芯片方案下,也会成为安全上的一个漏洞。

Theory and Implementation of a Chosen-ciphertext Attack on DVB-CSA

The solution of chosen-ciphertext attack on DVB-CSA is introduced in this article.It includes key search,compression and storage,FPGA acceleration,security chip attack techniques.Based on the above,Novel-SuperTV developed a DVB-CSA decryption machine demo system.The demo system is composed of a terminal device with security chip and a decryption computer.It is able to decrypt the CW(control word) within a certain time(the equivalent of a CP period),and spreads to other terminals to watch encrypted programs....