Privacy-enhanced Internet storage: Non-interactive publicly verifiable 1-out-of-n encryption schemes

One of the main important uses of Internet is its ability to connect people through the use of email or Internet storage. However, it is often desirable to limit the use of email or Internet storage due to organization's restriction, avoiding spams, etc. In particular, emails with multimedia contents will take up a lot of spaces. In this paper, we propose cryptographic schemes that can be used to stop unwanted messages to be stored in the Internet server. We refer this technique as privacy enhancement for Internet storage, since the Internet server will not learn any information directed to its users, other than performing its task to deliver or stop the messages. Firstly, we describe a notion of non-interactive publicly verifiable 1-out-of-n encryption by proposing a model together with its security requirements. Then, we extend this notion to a publicly verifiable ring-to-1-out-of- n encryption, that provides sender anonymity. We note that the previously known interactive versions of the publicly verifiable 1-out-of-n encryption cannot be used to construct publicly verifiable ring-to-1-out-of-n encryption.