Abstract:In future internet architectures, end-to-end (E2E) secured personal messaging is essential. So here an E2E user two-way authenticated double encrypted messaging architecture based on hybrid RSA for private messaging is proposed. Our P2P protocol works over TCP protocol for creating direct connections in between, with IPv4 broadcast options to discover peers on the same LAN. Our protocol implements perfect forward secrecy using Diffie-Hellman key exchange with renegotiation capability in every session with optimal asymmetric encryption padding and random salts. For making hybrid RSA with double encryption, in encryption level, main RSA is integrated with efficient RSA to give more statistical complexity. In the decryption process, the CRT is used for very high efficiency with integration with shared RSA. Our architecture also gives a hassle-free, secure, peer-to-peer, strong and reliable platform with E2E encryption for private messaging and it can also work with future internet architectures.Keywords: Chinese remainder theorem; CRT; Diffie-Hellman; perfect forward secrecy; PFS; optimal asymmetric encryption padding; OAEP; shared RSA; efficient RSA; hybrid RSA.Reference to this paper should be made as follows: Bhattacharjya, A., Zhong, X. and Wang, J. (2018)