A data processing method, wherein the method is applied to a data processing system, the system comprises a central processing unit, CPU, at least one advanced high-performance bus, AHB, a memory encryption/decryption, MED apparatus, and a memory, and the method comprises: receiving, by the MED apparatus, a data write command, wherein the data write command comprises to-be-written data and a address to which data is to be written; encrypting, by the MED apparatus, the to-be-written data; scrambling, by the MED apparatus, the address to which data is to be written; and saving, by the MED apparatus, a cyclic redundancy check CRC code of the to-be-written data and encrypted to-be-written data in the memory according to the scrambled address to which data is to be written; wherein after the saving, by the MED apparatus, a CRC code of the to-be-written data and encrypted to-be-written data in the memory according to the scrambled address to which data is to be written, the method further comprises: receiving, by the MED apparatus, a data read command, wherein the data read command comprises a address from which data is to be read; reading, by the MED apparatus, the to-be-read data and a CRC code of the to-be-read data from the memory according to the address from which data is to be read; performing, by the MED apparatus, a CRC check on the to-be-read data according to the CRC code that is of the to-be-read data and that is read from the memory; and when the CRC check succeeds, sending, by the MED apparatus, decrypted to-be-read data to the CPU by using the AHB. receiving, by the MED apparatus, a data write command, wherein the data write command comprises to-be-written data and a address to which data is to be written; encrypting, by the MED apparatus, the to-be-written data; scrambling, by the MED apparatus, the address to which data is to be written; and saving, by the MED apparatus, a cyclic redundancy check CRC code of the to-be-written data and encrypted to-be-written data in the memory according to the scrambled address to which data is to be written; wherein after the saving, by the MED apparatus, a CRC code of the to-be-written data and encrypted to-be-written data in the memory according to the scrambled address to which data is to be written, the method further comprises: receiving, by the MED apparatus, a data read command, wherein the data read command comprises a address from which data is to be read; reading, by the MED apparatus, the to-be-read data and a CRC code of the to-be-read data from the memory according to the address from which data is to be read; performing, by the MED apparatus, a CRC check on the to-be-read data according to the CRC code that is of the to-be-read data and that is read from the memory; and when the CRC check succeeds, sending, by the MED apparatus, decrypted to-be-read data to the CPU by using the AHB. receiving, by the MED apparatus, a data read command, wherein the data read command comprises a address from which data is to be read; reading, by the MED apparatus, the to-be-read data and a CRC code of the to-be-read data from the memory according to the address from which data is to be read; performing, by the MED apparatus, a CRC check on the to-be-read data according to the CRC code that is of the to-be-read data and that is read from the memory; and when the CRC check succeeds, sending, by the MED apparatus, decrypted to-be-read data to the CPU by using the AHB.