Research Of Chameleon Hash Based On LWE Problem And Its Application In Consortium Blockchain

The chameleon hash function is a special hash function with trapdoors.If you grasp the trapdoor information,you can find the collision in polynomial time.The existing construction schemes are mostly based on some mathematical problems,but with the advent of the quantum computing era,the security of traditional chameleon hash functions based on factorization and discrete logarithm problems is threatened.Therefore,it is urgent to design a new chameleon hash function construction scheme that can resist quantum attacks(such as based on difficult problems on the lattice).In addition,because the traditional hash function is widely used in blockchain technology,the blockchain has non-editable characteristics,which makes some applications under the support of this technology suffer malicious attacks.Traditional blockchain technology faces the problems of regulatory lack and resource occupation.Therefore,the chameleon hash function has the characternstics of trapdoor information,and it is introduced into the blockchain technology to design a redactable blockchain construction scheme.It is also practical to expand the application scope of the blockchain technology and improve its security.Based on the above problems,according to the characteristics of the chameleon hash function and applied it to the consortium blockchain technology to carry out the following research work:(1)A construction scheme LWE-CHF of a new chameleon hash function is proposed.Based on the lattice error learning problem(LWE),a trapping gate fast generation algorithm constructed by tool matrix is combined with a simple linear function gA(s,e)=sT+eT mod q to propose a new chameleon hash function.The security of LWE-CHF scheme depends on the difficult problem of LWE on the lattice.It has anti-collision and trapezoidal collision,can resist quantum attack,and the calculation time of hash value is average.(2)A basic framework for a new redactable blockchain is proposed.LWE-CHF and secret sharing scheme are introduced in the blockchain technology.The secret sharing scheme performs key management on the trapdoor information of LWE-CHF.The trapdoor information is used in matrix form by introducing Godel coding before performing secret sharing.Modifications,deletions,and additions can be made on the new redactable blockchain.(3)In the Linux environment,the implementation and analysis of the above schemes are performed using the C++ language.The performance analysis of the new chameleon hash function shows that LWE-CHF has good avalanche and diffusion effects,and the computational time complexity of grasping the trapdoor collision is 0(n);through the cpp-ethereum source code analysis,LWE-CHF The integration with the secret sharing scheme into the consortium blockchain shows that the redactable blockchain has practical value.