Improvement And Application Of The Aes Algorithm Based On Multi-core Android Platform

With the development of Mobile Internet, Android became the main mobile operating system. At the same time, information security is getting more and more attention, encryption as a means of information protection is also moving forward. In the symmetric encryption algorithm, AES algorithm has replaced the DES algorithm as the new encryption standard. Most of the existing AES algorithms are based on the single core processor, which is mainly based on serial. Due to the Moore’s law encountered a bottleneck, the multi-core processor came into being, and become the basic configuration of most Android devices. Multi core processor achieve the true sense of the multi-thread parallel computing.The paper first summarizes the layered architecture of Android platform and its security mechanism, then according to the analysis of the implementation process of AES algorithm, put forward the improvement scheme for the round transformation and the CTR mode plaintext packet. In the analysis of the round transformation, it is concluded that the Shift Rows transform does not have to wait until the SubBytes transform is completely finished. Similarly, the AddRoundKey transform does not have to wait until the MixColumns transform is complete. By changing the implementation process of the algorithm, the process of the implementation of the parallel processing is improved. Block cipher scheme based on CTR model, because the CTR mode does not depend on each other, the encryption algorithm can be executed in parallel with the block. Two kinds of improved schemes are under particular experimental conditions tested by multiple measurements to obtain the average value of the experimental data, the test results of two schemes show that the encryption speed obviously improved.In the end, according to the security mechanism of Android’s native Sqlite database, the improved AES algorithm is applied to the database encryption, then rebuild the library file, use the JNI way for the application to provide a database with encryption function, and no need to modify the Android system source code. The encrypted database can not be accessed directly through the database software, which can improve the security of Android application database.