This document proposes techniques to improve data transmission efficiency and security in wireless sensor networks. It discusses how the LEACH routing protocol is commonly used in WSNs but has limitations regarding energy efficiency and network lifetime. The paper proposes using a two-cluster head approach in LEACH to improve energy balancing and reduce transmission delays. It also proposes using the RC-6 encryption algorithm to securely transmit data in WSNs. Simulation results show the proposed approaches improve energy efficiency and extend the network lifetime compared to traditional LEACH and unsecured data transmission.