基于DTMF信号的智能手机外部攻击及防御方法  

External attack method for smartphone based on DTMF signal and defense method

作　　者：申兴发[1] 杨健 冉德纲 Shen Xingfa;Yang Jian;Ran Degang(School of Computer Science&Technology,Hangzhou Dianzi University,Hangzhou 310018,China)

机构地区：[1]杭州电子科技大学计算机学院,杭州310018

出　　处：《计算机应用研究》2020年第6期1812-1815,1820,共5页Application Research of Computers

基　　金：国家自然科学基金资助项目(61672198);杭州电子科技大学学科交叉创新团队建设项目。

摘　　要：提出的基于DTMF信号的智能手机外部攻击方法,可以在用户不被察觉,且与用户手机无交互情况下进行有效攻击。该方法对用户某些重要按键操作进行录音;然后对录音数据在时域上进行双阈值的端点检测,提取信号的有效区域;再将有效区域通过Goertzel算法转换到频域进行数字分类;对比通过比照DTMF编码表得到用户所有按键数据。实验结果表明,该方法在10 d B信噪比,且与用户手机无交互的条件下能破解80%以上的按键数据。最后,给出了相应的防御方法。This paper proposed an external attack method for smartphone based on DTMF signal,which could attack effectively without the user being aware and without interaction with the smartphone. Firstly,it recorded some important keystroke operation of user. Secondly,it performed double-threshold endpoint detection in time domain to extract the effective area of the signal. Thirdly,it converted the effective area to frequency domain by Goertzel algorithm for digital classification. Finally,all the keystroke data of the user were obtained by comparing the DTMF coding table. The experimental results show that the method can decipher more than 80% of the keystroke data under the condition of 10 dB signal-to-noise ratio and no interaction with the smartphone. In order to that,it proposed a defense method.

关 键 词：智能手机 内部攻击 DTMF信号 外部攻击 端点检测 GOERTZEL算法 

分 类 号：TN918.91[电子电信—通信与信息系统]