Research On State Obfuscation Of Cryptography Algorithm Firm IP Core

With the shrinking of semiconductor process,the number of transistors on a single Very Large Scale Integration(VLSI)chip has been increasing,which has greatly promoted the development of electronic technology.Meanwhile,manufacturing complexity and production cost of the foundry increasing dramatically,it is difficult to complete the design and sales of chips in a company,which resulting in more and more technology companies participating in the Integrated Circuit(IC)supply chain.This poses a threat to Intellectual Property(IP)core.So how to protect the IP core effectively is becoming an urgent problem.Hardware obfuscation technology is an important means of current IP core protection,it means hiding the functionality of the circuit by modifying the IP/IC design.This paper explores the limitations of existing IP solid core obfuscation methods,through the study of an intensive study of hardware obfuscation in-depth,and proposes state obfuscation research method of cryptography algorithm firm IP core.The following list provides a more detailed overview of this dissertation.1.Low-overhead obfuscation design based on Minimum Spanning Tree-Finite State Machine,(MST-FSM): Modifying the original FSM in the circuit can achieve the purpose of obfuscating and protecting the original circuit,but it will increase the overhead of area and power consumption.So this paper proposes a MST-FSM obfuscation method based on the minimum spanning tree algorithm.The obfuscation states interconnection relationship of the obfuscation FSM are determined by Kruskal algorithm,and they are automatically generated and embedded to the IP core by the C language program.In the obfuscation evaluation mechanism,three evaluation metrics-obfuscate potency,obfuscate resilience and performance overhead are proposed.2.Design of obfuscation cryptographic algorithm based on state deflection strategy: When the effective state of the FSM in the circuit works normally,the safety protection mechanism of the circuit will be invalid,and there are threats such as register strong attack and hardware Trojan attack.So,this paper combines the AES cryptographic algorithm obfuscation mechanism to propose a state deflection strategy.The deflection strategy with redundancy and black hole states are used to realize the obfuscation of FSM,and the bit flip method is used to realize the combinational logic obfuscation.Finally,the proposed hardware obfuscation AES algorithm is designed in SMIC 65 nm CMOS process.3.Obfuscate algorithm design based on fully homomorphism: The fully homomorphic method allows the encrypted circuit to perform a specific operation and then decrypt the result.The decrypted result is equal to the result of the same operation performed on the original circuit.In the design process of IP core,due to unreliable third-party contact design data,it will provide opportunities for hardware Trojans and side channel attack,etc.This paper proposes a obfuscation algorithm based on fully homomorphism technology.Encryption module encrypts the input data and use the encrypted data to perform operations.In the data output stage,by controlling the key of KS to obfuscation output.Consequently,it is improve the security of the IP core.4.Design of cryptographic algorithm IP core based on collaborative obfuscation: The existing single-level obfuscation method exposes more and more limitations,such as low security of singlelevel obfuscation,the possibility of internal IP core being reversed.If the attacker comes from within the design team,the chip information can be easily disclosure.In view of this,this paper proposes a multi-level collaborative obfuscation method based on collaborative point of behaviorlevel obfuscate,circuit-level obfuscation,and physical-level obfuscation.And VLSI circuit is implemented based on Camellia cryptographic algorithm to improve the safety and reliability of the circuit.This paper uses TSMC and SIMC 65 nm CMOS process for circuit design,and mainly uses Cadence and Synopsys' EDA software for overall implementation.Through research on the state obfuscation method of cryptographic algorithm IP solid core,this paper solves the security problem of IP solid core to some extent.And at the same time the security of obfuscation is considered,and the chip not only meets the performance requirements,but also further optimizes in area and speed consumption during the VLSI design process.