基于随机性检测的链路层加密数据盲识别方案

Independent Identification of Encrypted Data in Data Link Layer Based on Randomness Test

为识别链路层加密数据,构建了以块内频数检测为主的链路层加密数据盲识别方案。针对分块长度影响块内频数检测识别率的问题,提出了基于方差原理的比特序列分块长度值选择方案。针对块内频数检测对长度较短的比特序列的识别能力有限的问题,提出了基于随机抽样原理的比特序列信息提取方法,以提高对未加密比特序列的识别率。最后,以某无线网络链路层数据的识别为例,对提出的方案进行了验证。结果表明,提出的方案对链路层加密数据具有较高的识别率,相关成果可为进一步的协议识别技术研究打下基础。

To identify the encrypted data of data link layer,an independent identification scheme was proposed by main- ly using the technique of frequency test within a block. As the identification rate of frequency test within a block is im- pressionable to the size of the block, a block size chosen scheme was provided based on the principle of variance. Fur- thermore, as the identification ability of frequency test within a block is also limited to short bit sequence, random sam- piing was introduced into its information extraction process to heighten the identification rate. Eventually, by taking the link layer bit sequence of a wiriness network as the identification object,the identification rate of the proposed schemes was verified. Experimental results demonstrate that the proposed schemes have high rates to identify encrypted data of data link layer and the correlative research paves the way for the further protocol identification research.