The increasing integration of wearable health monitoring devices in our daily lives has brought about tremendous advancements in healthcare. However, the sensitive nature of health data being transmitted by these devices necessitates robust security measures. This paper addresses the security challenges associated with the MQTT (Message Queuing Telemetry Transport) protocol commonly used for communication in wearable health monitoring devices. Specifically, we explore the application of lightweight block ciphers, focusing on Advanced Encryption Standard-Counter with CBC-MAC (AES-CCM-128 bit), to enhance the security of data transmission.