Research And Evaluation On The Implementation Security Of Hybrid Cryptographic Systems

Encryption system is generally divided into two classes: symmetric encryption and asymmetric encryption systems.However,security or efficiency problems will be encountered with only one of them.Therefore,in order to ensure security and efficiency at the same time,modern encryption system combines symmetric encryption system with asymmetric encryption system together,resulting a hybrid encryption cryptosystem.Hybrid encryption system contains two stages:key agreement based on public key encryption algorithm and data encryption based on symmetric encryption algorithm.However,in the face of the threat of quantum computer,the traditional public key encryption algorithms,such as RSA(Rivest,Shamir,Adleman)and ECC(Elliptic Curve Cryptography),are no longer safe,so it is the inevitable trend with post-quantum cryptography algorithms to replace the traditional public key encryption algorithms.In terms of side-channel analysis,this research evaluates the implementation security of modern hybrid encryption system based on three kinds of actual cryptographic chips,aiming to improve the security of hybrid cryptosystem from both the attack and defense sides.Firstly,the security of first stage—key agreement based on post-quantum cryptography is researched.This paper proposes a differential electromagnetic side-channel attack method to recover the private key,taking supersingular isogeny elliptic curve cryptography as an example,which is a candidate of National Institute of Standards and Technology.On this foundation,a window-based countermeasures is proposed to prevent differential electromagnetic side-channel attack.Then,the security of second stage— data encryption is studied.Aiming at the most popular symmetric encryption algorithm—AES(Advanced Encryption Standard),this paper proposes three kinds of random delay countermeasures to prevent traditional power analysis attacks at two different platforms.In addition,an attack framework based on wavelet analysis is proposed to response to random delay countermeasures,including wavelet-based denoising,wavelet-based alignment and wavelet-based key recovery.Moreover,the attack performance of the attack framework is evaluated and analyzed comprehensively.Through this research,it is found that both phases of hybrid encryption system may be threatened by side-channel analysis.More attention should be paid to the security of its implementation on the actual cryptographic chips.The innovation of this paper is that effective attack methods are proposed to threaten the post-quantum cryptography and symmetric encryption algorithm with random delay countermeasures on three different cryptographic chip platforms—8-bit general purpose microprocessor,ARM processor and FPGA(Field Programmable Gate Array),which provides theoretical and practical guidance for the security research of hybrid encryption system.