With the manifestation of the Internet of Things (IoT) and fog computing, the quantity of edge devices is escalating exponentially all over the world, providing better services to the end user with the help of existing and upcoming communication infrastructures. All of these devices are producing and communicating a huge amount of data and control information around this open IoT environment. A large amount of this information contains personal and important information for the user as well as for the organization. The number of attack vectors for malicious users is high due to the openness, distributed nature, and lack of control over the whole IoT environment. For building the IoT as an effective service platform, end users need to trust the system. For this reason, security and privacy of information in the IoT is a great concern in critical infrastructures such as the smart home, smart city, smart healthcare, smart industry, etc. In this article, we propose three information hiding techniques for protecting communication in critical IoT infrastructure with the help of steganography, where RGB images are used as carriers for the information. We hide the information in the deeper layer of the image channels with minimum distortion in the least significant bit (lsb) to be used as indication of data. We analyze our technique both mathematically and experimentally. Mathematically, we show that the adversary cannot predict the actual information by analysis. The proposed approach achieved better imperceptibility and capacity than the various existing techniques along with better resistance to steganalysis attacks such as histogram analysis and RS analysis, as proven experimentally.