A Comparative Performance Analysis of ElGamal and ECC-AES Hybrid Cryptosystems for Secure Communication

In the age of mobile communication, the Internet of Things (IoT), and blockchain technologies, secure and efficient data encryption is essential. This study presents an experimental comparison between two cryptographic methods: ElGamal (1024-bit) and a hybrid encryption model combining Elliptic Curve Cryptography (ECC, 256-bit) with Advanced Encryption Standard (AES). The aim is to evaluate and compare their performance regarding key generation time, encryption and decryption speed, and ciphertext size to determine their suitability for real-world applications. The experimental results show that ECC + AES significantly outperforms ElGamal in all tested metrics. ElGamal recorded a key generation time of 0.258 seconds, encryption time of 0.0093 seconds, and decryption time of 0.0049 seconds, producing a ciphertext size of approximately 256 bytes. In contrast, ECC + AES achieved key generation times of 0.0008 seconds (sender) and 0.0001 seconds (receiver), with encryption and decryption times of 0.0008 seconds and 0.00005 seconds, respectively. It also produced a much smaller ciphertext of around 32 bytes while supporting actual text messages like "CARLOS," compared to ElGamal's number-only input. These findings demonstrate that while both encryption methods provide strong security, ECC combined with AES is much more efficient and practical for environments requiring fast processing, smaller data sizes, and real-time communication, such as secure messaging, IoT networks, and low-power devices. This study provides concrete data supporting adopting ECC-based hybrid systems over traditional methods like ElGamal for modern cryptographic applications.