In this paper, we propose a secure and efficient protocol to transmit fingerprint images from a fingerprint sensor to a client by exploiting characteristics of fingerprint images. To guarantee the integrity/confidentiality of the fingerprint images transmitted, a standard encryption algorithm is employed. Because the fingerprint sensor is computationally limited, however, such encryption algorithm may not be applied to the full fingerprint images in real-time. To reduce the computational workload on the resource-constrained sensor, we apply the encryption algorithm to a nonce for integrity and to a specific bitplane of each pixel of the fingerprint image for confidentiality. Experimental results show that the integrity/confidentiality of the fingerprint images can be guaranteed without any leakage of the ridge information. Also, the image-based selective bitplane encryption can be completed in real-time on embedded processors.