Аннотация:Steganography is one of the most powerful tools for information hiding. In this paper, we have modified least significant bit (LSB) substitution method for data hiding. Conventional LSB technique uses the least significant bit of consecutive pixels for embedding the message which draws suspicion to transmission of a hidden message. If the suspicion is raised, then the goal of steganography is defeated. Still LSB technique is the most widely used as it is simple. In our implementation pixels to be substituted with information are selected randomly which makes it superior to the conventional approach. The robustness of the algorithm is further increased by using keyless steganography. This paper proposes a novel technique to hide information in a 24 bpp RGB image using modified LSB substitution method.