With the rapid application growing of internet and wireless network, information security becomes significant to protect commerce secret and personal privacy. Encryption algorithm plays a crucial role for information security guarantee. In this paper, we evaluate the performance of two symmetric key encryption algorithms: CAST and RC5 commonly used for network data encryption. We analyzed the encryption security, evaluated encryption speed and power consumption for both algorithms. Experimental results show that CAST algorithm runs faster than RC5 algorithm while consumes less power, which is demonstrated that CAST is more suitable for wireless network application.