This article proposes Chua’s oscillator-based RSA algorithm for secure communication. The prime numbers, required in the RSA algorithm, are generated with the help of different output parameters of the Chua’s oscillator. These prime numbers are highly random due to the non-linear and unpredictable (or chaotic) behaviour of Chua’s oscillator. With this improved version of RSA, a highly reliable and secure system has been achieved. Additional security has been provided in the communication system by making the authenticated masked public key. The synchronization is also done with the help of Chua’s oscillator to enhance security and to avoid receiving the wrong messages. The masked public key with one output parameter of Chua’s oscillator is incorporated to provide the authentication in the communication system. The four algorithms are discussed in this paper to make secure, reliable, and authenticated communication system.