Trustworthy And Hierarchical Email System Based On Identity-Based Encryption

We construct IBE schemes in some new ways, and solve some openproblems in this field , such as building identity based systems that are chosen ciphertext security in the standard computation model rather than the random oracle model (proposed by [2]). In addition, we expand Shamir' s original idea of IBE system: we not only make authentication of Receiver' s identity without the involvement of the sender, but also make authentication of sender's identity without the involvement of the Receiver. Furthermore, we realize, for the first time, some functions in IBE schemes, such as instant revoking of receiver' s identity and sender' s identity. At last we propose a trustworthy and hierarchical Email system based on our IBE, which adds many new functions to traditional Email system , such as authentication of Email' s source address, resisting junk Emails, receipt related to Email content , generating evidence of sending Email (related to source address, content of the Email), etc. Additionally, we can expand this system to a hierarchical system by a method simpler than all existing ones [10,13].