In this paper, we propose a lightweight security framework for Internet of Things (IoT) communication that combines key exchange based on Elliptic Curve Cryptography (ECC) over extension fields with pseudorandom stream generation using the Cyclic Vector Multiplication Algorithm (CVMA) and the Continuously Decimalized Maximum-length (CDM) method. By implementing ECC over extension fields $\mathrm{GF}(p^m)$, we leverage CVMA for efficient field arithmetic operations with arbitrary parameters such as characteristic and degree, enabling flexible and optimized computations tailored to specific hardware platforms. CDM realizes an efficient design for random number generation with long period and high linear complexity. Furthermore, using a positive integer parameter of CVMA as like a session key, this paper proposes a lightweight secure communication framework for real-time IoT applications.
