In this paper, we analyze the security of Least Significant Bit (LSB) embedding for hiding messages in high-color-depth digital images. We introduce a powerful steganalytic technique that enables us to reliably detect the presence of a pseudorandom binarymessage randomly spread in a color image. We estimate the probability of both false detections and missing a secret message. The method is based on statistical analysis of the image colors in the RGB cube. It is shown that even for secret message capacities ofO.l -0.3 bits per pixel, it is possible to achieve a high degree of detection reliability.