Identity-based Linearly Homomorphic Cryptosystem And Its Applications

As the fast developing of the Internet,the problems of data security and privacy protection on the network are becoming increasingly serious.Therefore,how to ensure data security and privacy protection in the network has become an important research topic.Aiming at this problem,this paper proposes an identity-based linearly homomorphic cryptosystem.The cryptosystem is composed of an identity-based linearly homomorphic encryption scheme and linearly homomorphic signature scheme,which shares system parameters and saves storage costs.Identity-based linearly homomorphic encryption scheme is used for identity-based encryption of data and for linear computation of ciphertext data.The identity-based linearly homomorphic signature scheme is used to aggregate signatures to ensure the integrity of ciphertext.Electronic voting is based on cryptography knowledge,through network technology and electronic devices to achieve voting functions.Electronic voting is more and more used in practice because it has many features such as convenient operation,saving resources,and so on.How to ensure the privacy,anonymity,integrity and security in the voting process has become a concern.o solve these problems,this paper implements an electronic voting system on an identity-based linearly homomorphic cryptosystem combined with blockchain technology.Aiming at the issues of privacy,anonymity,and integrity in electronic voting,an identity-based linearly homomorphic cryptosystem was introduced.The identity-based linearly homomorphic encryption scheme is used to encrypt the result of the vote and to perform a linearly homomorphic calculation on the encrypted vote results,which can effectively solve the problems of privacy and anonymity.The linearly homomorphic signature scheme can aggregate multiple signatures into one signature,which reduces the calculation cost and verification cost of the signature.Blockchain technology is a distributed database technology solution,which has the characteristics of decentralization and detrust.It also has the characteristics of security,reliability,immutability,anonymity,etc.Its decentralized and distributed network structure guarantees the transparency of the network,and also prevents malicious voting or tampering with votes and cheating by cheating votes.Its anonymity can hide the personal information of voters and protect personal privacy.As a development model of the next generation grid,smart grid combines traditional grid and information and control technology.It allows distributed and bidirectional transmission of power flow and information flow,and it can respond reliably and effectively.As a intelligent terminal of the smart grid,smart meters have functions such as data protection,power display,low powerconsumption,anti-theft and so on.In the smart grid,an isolated smart meter is a kind of smart meter that is generated in order to solve problems such as geographical location and natural disasters.There are data security and privacy protection issues in the smart grid,and the data and privacy of such isolated meter users are also worth protecting.Therefore,in this paper,an isolated smart meter measurement protocol is designed on the identity-based linearly homomorphic cryptosystem to solve the data security and privacy protection issues of isolated meter users.This paper mainly studies identity-based linearly homomorphic cryptosystem and its two applications.The main work is as follows: 1)This paper proposes an identity-based linearly homomorphic cryptosystem and gives specific algorithms and security proofs.2)This paper analyzes the existing problems of electronic voting and combine blockchain technology to implement an identity-based linearly homomorphic cryptographic electronic voting system.3)This paper analyzes the characteristics and current status of the smart grid,and design an identity-based isolated smart meter report protocol for the isolated smart meter.The protocol includes an identity-based linearly homomorphic encryption scheme and a linearly homomorphic signature scheme,and proposed security analysis against several attacks.