Outguess steganography online6/18/2023 Both these methods can carry only small amounts of secret data.Īn even more powerful method is the bit-plane complexity segmentation (BPCS), presented in the late 1990s by computer scientists Richard Eason and Eiji Kawaguchi. There's also palette-based image steganography, in which data is encoded into the LSB of the image palette. When JPEG images are used, attackers can employ a technique called discrete cosine transform (DCT), which allows sending data by altering the LSBs of the DCT coefficients of an image. There are a few variations of this method. Of course, the color of the pixel will be different, but the change will be imperceptible to the human eye. (When converting from binary to decimal, you multiply the "1" on the left by 128 and the "1" on the right by 1,) Thus, manipulating the right-most bit of the sequence makes little impact. It allowed the manipulation of roughly 15% of an image by changing the least important bit of each byte, the one farthest to the right.įor instance, in the 11001101 byte, the first "1" on the left is the heaviest, while the "1" on the right carries the least weight. One of the oldest ones is the least significant bit (LSB) substitution method, which became popular during the mid-1980s. Several techniques could be employed to achieve that. Also, both files are the same size, 786,486 bytes. The initial photo (Lenna.bmp) and the changed one (Lenna_stego.bmp) look exactly the same to the naked eye. To show this, researchers at Kaspersky camouflaged the first ten chapters of Nabokov's novel Lolita inside the standard image Lenna. Still, if users look at the original photo and compare it with the altered one, they can't tell the difference. "We often see it being used as the initial entry point, and once the threat actors are in the network, there are more tools and code that they will use to move laterally," Jon Clay, vice president of threat intelligence at Trend Micro, says.įrequently, the secret data is cleverly hidden inside an image by manipulating a few bits. Steganography is one way malicious actors fly under the radar.
0 Comments
Leave a Reply. |