Design Of Encryption And Decryption Subsystem Based On Embedded CPU

With the rapid development of Information technology, the dependence of people towards informatization gets higher and higher, the consequent information security must be considered in SoC design. As the most safe and reliable protect mechanism, Data encryption technology is the critical work in the information security. To shorten the develop period of chips, subsystem integrated by several IP modules with specific function can contribute great convenience to rapid Integration of SOC,which develops from the IP reuse technology. There are important practical significance to develop an encryption and decryption subsystem based on embedded CPU from the above two sides. The main research and innovation includes:This paper proposes an architecture of encryption and decryption subsystem bases on homemade embedded CPU CK803and widely used AMBA interconnected bus, upon generic architecture of general subsystem. Several encryptions such as DES、AES are supported. The power of system is decreased effectively by clock-gating technology. The work flow is also introdunced.As one of important encryption modules, a high-performance DES module supporting DES and3DES algorithm simultaneously based on the relationship of DES and3DES is designed. The result of every round operation is stored in registers and the last result of algorithm will be figured out in the control of operation mode and number of rounds.As the small area and good performance, this DES module meets the need of practical application.This paper designs a kind of AES encryption and decryption module, in which the hardware resource of encryption and decryption are reused. After the brief introduction of math background and algorithm principle of AES, the design of IP and the realizition of internal mose module are presented in detail. The AES module which occupies less resource and covers comprehensive functions, has good value in practical application.To get the target that the subsystem can be configured and integrated easily,By designing two platform scripts including the XML script and generator script of subsystem encryption based on SoC Integrator of Hangzhou C-SKY Microsystem Corporation, this paper Integrate the subsystem to platform of C-SKY and commite to the library, which gets the target that the subsystem can be configured and integrated easily. As the SoC containing encryption and decryption subsystem have configurable functions and can be developed within short period, it plays an important role in application.