Improved Efficient Identity-Based Encryption Scheme

This paper has elaborately researched the authority trust problem in the identity-based encryption (IBE) , making the discussed schemes stronger and more security. And also researched another security problem of the certificate less public key encryption (CL-PKE), which is the denial of decryption (DOD) attack. Through the DOD research, the CL-PKE not only can resist center forging attack but also can resist the DOD attack launched by key distribution center and outside users.