The rapid growth of communication over the Internet and the development of the Internet of Things (IoT) raise the impact of cryptography on information security. Given that images are the most commonly used and shared data over the internet, the development of a secure algorithm to secure this transfer is the main purpose of many researchers. This paper presents an efficient chaos-based encryption algorithm using the two-dimensional Beta chaotic map 2D-BCM assuring medical image security during transmission and storage. The security analysis carried out indicates that the proposed encryption scheme is secure against various forms of attacks including statistical, differential, chosen-plaintext, and brute force attacks. Therefore, the cipher is well-suited for utilization in real-time IoT applications.