USB (universal serial bus) flash disk encryption key storing method capable of preventing cold boot attack

The invention relates to a USB (universal serial bus) flash disk encryption key storing method capable of preventing cold boot attack and belongs to the technical field of data security. According to the method, the storing position of an encryption key in an internal storage is changed by modifying an Android kernel source code when a USB flash disk is encrypted through an AES encrypting algorithm, and the encryption key cannot be obtained by a cold boot tool. Specifically, a code of internal storage application of a crypto encrypting and decrypting algorithm information structure body is modified, and the structure body can be stored at the fixed position in the internal storage, namely, the internal storage which is used for storing command line parameters when equipment is started and the internal storage with the offset away from the beginning address of the internal storage as 0*100. The encryption key data are covered by the command line parameters when a system is restarted, and the encryption key cannot be obtained by cold boot attack. Compared with the prior art, the USB flash disk encryption key storing method changes the storing position of the encryption key of the encrypting algorithm of Android equipment by modifying a starting mirror image of Android equipment, the encryption key information can be covered after the equipment is restarted, the encryption key cannot be obtained by the cold boot attack, and the private data of a mobile phone can be further prevented from being obtained.