On the other hand, the DCT-based method offers lower capacity with increased visibility, but it is more robust. The performance analysis demonstrates that the LSB-based method can conceal more data with less visibility, however, it is vulnerable to simple image manipulation. In contrast, the second method yields an average PSNR of 38.4092 with a payload capacity of up to 8%. The first method achieves an average PSNR of 43.5292 with a payload capacity of up to 16% of the cover image. With N bits a Maximal LFSR will have (2N) - 1 states.

When considering the implementation of the LFSR, the bit width of the random number and the repeatability of the number need to be considered. The experimentation involves various 512x512 cover images. Implementation is relatively simple, a shift register with a number of terms XORd together to create the feedback term. A pseudo-random binary key that is generated through a nonlinear combination of eight Linear Feedback Shift Registers (LFSRs) controls this randomness. These methods embed the data in a random location with a random amount, further enhancing the level of obfuscation. Unlike other available methods that embed data in sequential order with a fixed amount. These methods enhance obfuscation by utilizing two layers of randomness: random pixel embedding and random bit embedding within each pixel. The second method is the functioning in the frequency domain which hides the secret message within the LSBs of the middle-frequency band of the discrete cosine transform (DCT) coefficients. The first is operating in the spatial domain which utilizes the least significant bits (LSBs) to conceal a secret message. This paper presents two distinct methods. Steganography involves concealing information by embedding data within cover media and it can be categorized into two main domains: spatial and frequency. Information hiding, Embedding data, Image security, Spatial domain Frequency domain, LSB, DCT, Randomness, LFSR, Payload capacity Abstract

Department of Mathematics, College of Science, University of Baghdad, Baghdad, Iraq

Linear feedback shift registers