Building Secure and Anonymous Communication Channel: Formal Model and its Prototype Implementation
This addresses the need for secure and anonymous communication for users and service providers, representing an incremental improvement over existing techniques.
The paper tackled the problem of building a secure and anonymous communication channel by proposing a protocol that combines identity-based encryption and group signatures to enable anonymously authenticated communication without revealing user identities or IP addresses, and demonstrated its feasibility with a proof-of-concept implementation showing practical performance compared to SSL.
Various techniques need to be combined to realize anonymously authenticated communication. Cryptographic tools enable anonymous user authentication while anonymous communication protocols hide users' IP addresses from service providers. One simple approach for realizing anonymously authenticated communication is their simple combination, but this gives rise to another issue; how to build a secure channel. The current public key infrastructure cannot be used since the user's public key identifies the user. To cope with this issue, we propose a protocol that uses identity-based encryption for packet encryption without sacrificing anonymity, and group signature for anonymous user authentication. Communications in the protocol take place through proxy entities that conceal users' IP addresses from service providers. The underlying group signature is customized to meet our objective and improve its efficiency. We also introduce a proof-of-concept implementation to demonstrate the protocol's feasibility. We compare its performance to SSL communication and demonstrate its practicality, and conclude that the protocol realizes secure, anonymous, and authenticated communication between users and service providers with practical performance.