Research And Implementation Of The Identity Based Encryption

Using the user's Identity as a public key is the important function for Identity Based Encryption(IBE)system.This eliminates the need to distribute the public key certificate.Since Boneh and Franklin proposed the first practical IBE system,the research of the IBE system has entered a new era.However,before the Dual System Encryption(DSE)is put forward,the partitioning strategy is used in the proving security of IBE system.The typical model is Selective-ID model.Although the partitioning strategy has proved useful,it also has limits and defects.For example,when the IBE system which uses the partitioning strategy wants to be a fully secure system,it needs more public parameters.And it has not adapted to proving security of Hierarchical ID-Based Encryption(HIBE)scheme and Attribute-Based Encryption(ABE).The Dual System Encryption is different from the partitioning strategy.When a scheme which using the latter prove security,the simulator needs to partition identity space into two parts,the identity space for which it can create private keys and the identity space which it can use in the challenge ciphertext phase.There is no such requirement in the Dual System Encryption.In this paper,the partitioning strategy and Dual System Encryption are analyzed in detail,this makes us have a deeper understanding of how to use Dual System Encryption in proving security,and a contradictory problem need to be solved when using the Dual System Encryption to prove security.In this paper,through analyzing Waters HIBE scheme,we find that the public parameters have redundancy,and HIBE scheme can be simplified.Therefore,this paper constructs a less of public parameters,more efficient and fully secure HIBE scheme,and gives the proving security which use dual system encryption.Finally,we implement the original HIBE and simplified HIBE through using the Java programming language,and proceed the efficiency comparison in them.