一种基于空中接口和核心网协同的LTE系统密钥推演方法

摘要

This paper put forward a cooperating method for key derivation based on the idea of combination of radio interface and core network.It produced the radio child-keys according to the security algorithm list provided by plain radio message and obtained parent-key,and decided the right key by comparing the plain context and the decrypted context.It proves that the correct rate of key derivation is more than 90％ in the case that the symbol error rate (SER) is less than 10-3 according to the analysis of feasibility.Therefore it has practical application values.%从窃听方的角度,基于空中接口与核心网协同的思想提出了一种LTE系统密钥推演方法.首先,在实现根密钥同步的基础上,根据空中未加密信息提供的安全算法列表,遍历有限安全算法集;然后,将遍历的安全算法与获取的父密钥共同作为参数,通过密钥生成函数生成空中接口子密钥;最后,通过比对明文和解密密文确定密钥.可行性分析表明,窃听方可以利用该方法推演出空中接口子密钥;误码率小于10-3时,可使密钥推演成功率达到90％以上,具有实际应用意义.