Symmetric white box encryption method with unfixed key and apparatus

Abstract

The invention provides a symmetric white box encryption method with an unfixed key. The method comprises the following steps: performing key expansion by using a symmetric encryption method to acquire multiple turns of encryption keys Kn; step 2, replacing the multiple turns of encryption keys Kn to acquire replaced keys Kn'; step 3, generating a white box library; step 4, transmitting the white box library and the replaced keys Kn' to a user; and step 5, performing white box encryption by a user on to-be-encrypted data by using the replaced keys Kn', and performing table lookup by using the white box library during the white box encryption to acquire ciphertext, wherein n represents the encryption turns of the symmetric encryption method. By adoption of the symmetric white box encryption method provided by the invention, the keys in the white box encryption are not only hidden, the white box library is separated from the keys, and users can set the keys by themselves, thereby being convenient and flexible.

Description

technical field [0001] The present invention relates to the field of computer security, and more specifically, the present invention relates to a symmetric white-box encryption method and device with an unfixed key. Background technique [0002] With the development of technologies such as wireless communication and the Internet, many devices can be connected to the Internet, including smartphones, tablets, cars, set-top boxes, wearable devices, smart home appliances (such as air purifiers), smart homes (smart cameras), etc. The networking of these devices has brought convenience to human life and production, and at the same time, it has given criminals an opportunity. Criminals can completely control and access hardware and software in some ways. The disassembly and static analysis of files, the control of the operating environment, combined with the use of control CPU breakpoints, observation registers, memory analysis, etc. to obtain passwords have a certain impact on the...

AI Technical Summary

Problems solved by technology

[0009] However, in this white-box encryption algorithm, the key is fixed, that is, the key is not transformed and directly combined with the nonlinear transformation of the algorithm to form a fixed part of the algorithm.

This white-box encryption algorithm with a fixed key cannot satisfy the user to set the key by himself. When encrypting, he only needs to enter the plain text and does not need to enter the key.

In IoT devices, once used, the keys of a batch of devices are the same, and its security is worrying. Therefore, in the IoT environment, there is an urgent need for a white-box encryption system with keys that can be dynamically set

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