Identity-Based Encryption And Its Practice In Electronic Voting Protocol

Modern Cryptography includes a very popular part which names Identity Based Encryption. In this system,the public key of user is directly derived from the information of his identity.For example,ID,e-mail and so on.If one user tends to communicate with another, he just needs to know the one's identity.However,the key generation procedure in the usual sense of public-key cryptography renders all public keys random.Consequently, it is necessary to associate a public-key with the identity information of its owner in an authentic manner.We have seen that such an association can be realized by a public-key authentication framework in PKI.But to establish the authentication framework makes the system complexity and cost,and it also makes to practice the system in real world hard.Instead of the public-key system,Identity Based Encryption can solve the problem easily.In Identity Based Encryption,the direct derivation of public keys can eliminate the need for certificates.Senders can send messages just using receivers' identity.Therefore, Identity Based Encryption reduces the authentication frameworks of PKI,provides the system's efficiency,and be more practical in electronic-voting,electronic-commerce and other protocols.We intensively research the characteristic and application of Identity Based Encryption in the paper.Firstly,we study the chief four parts of Identity Based Encryption: setup,key exact,encryption and decryption.And the most important idea is the key generation procedure,which has the following step:private-key = F(master-key,public-key) Of course,In order for a computed private-key to be kept secret,the computation must not be public.It is restricted to a privileged principal(a trusted authority,TA). Secondly,the Identity Based Encryption system of Dan Boneh is analyzed,which is based the pairings in Elliptic Curve.We also proved that it is provable security.Then,we expand and practice the system by using the characters of pairings.Thirdly,we compare the public-key system and the Identity Based system.Besides of the different definitions of public-key,the key generation procedures are comparable between these two systems. We research the differences further more in practice.At last,we propose an electronic selection protocol which is constructed by the main idea in Identity Based Encryption. We also prove the security of the new protocol.In a word,our research results mostly express as follows:(1) Study the IBE system of Dan Boneh,and research some problems in this system,for example the transmutations of the system;(2) Describe the differences between the public-key system and IBE system and tell the advantages of Identity Based Encryption;(3) Propose an electronic selection protocol using the advantages of Identity Based Encryption.