Encoding is one of the best techniques for retaining and checking information shared in the presence of third-party antagonists, via public news channels. In the encoding process, the stored or transmitted message is produced into gibberish or unreadable sort. The opposing system in which the destination node is unwilling to confirm the content of the encrypted message is called decoding. The processes of encoding and decoding are managed using encrypted keys that are communicated between the sender and a client exclusively. This procedure can be linked with any message mode, Such as audio, video, data with multimedia, or text. The modern role entails the well-known rivest, Shamir, Adelman (RSA) encoding and decoding message signals algorithm for time complexity. Experimental implementation has examined the effectiveness of the method proposed, showing that using Matlab simulations, how the time complexity works in RSA algorithm. The results of the proposed methodology indicated it is legal, consistent, powerful, and used in secure audio communications and that the recovered message signal within the time was strongly interpretable. The message signal should be encrypted or decrypt within the time so that the time complexity method is used in the RSA algorithm.