Biometric security measures are available at several locations along the data process that comprises the Internet of Things (IoT). Saving and transmitting biometric data in the format of images across public networks necessitates using a fast, seamless, secure encryption system capable of preserving biometric image data while protecting them. More encryption techniques are introduced in the IoT environment. However, it consumes high power and more computational complexity and provides less security. Hence, this paper proposed a novel security approach using optimal key-based elliptic curve cryptography (OKECC) for biometric images in IoT. In this system, the biometric images are initially collected from the FVC2004 DB-3 dataset. Then the image compression is performed using Modified Huffman Encoding (MHE) to diminish the encryption model's storage space and computation burden. After that, image compression is performed using OKECC to encrypt the compressed image. Finally, on the receiver side, the reverse encryption and compression process is done to retain the original image. The experimental results reveal that the proposed system offers better security than the existing systems for biometric images.