# High-Fidelity Steganography: A Covert Parity Bit Model-Based Approach  
[PERSON]  
1 College of Computing & Informatics, University of Sharjah, Sharjah P.O. transmitted messages makes it difficult for an attacker to identify the secret data. However, the unrecognizable format of the data also reveals the secrecy of the data, potentially triggering suspicion that the message may be a secret message, prompting an attacker to perform active attack methods such as delaying or tampering. As an alternative, data hiding techniques operate by hiding the secret message in an innocent cover medium to obtain a so-called \"stego\" medium. The generated stego medium should be very similar visually or statistically identical to the cover medium in order to prevent triggering suspicion that the sent message may contain secret communication. The field of data hiding has seen increasing attention over the past few decades due to the growing transmission of confidential messages via public shared media such as wireless networks and the internet [5]. A popular research topic in the data hiding field is to propose data hiding schemes that improve and compensate for the contrasting attributes of stego quality (imperceptibility), robustness, and hiding capacity [6; 7; 8]. The security attribute is concerned with the ability of an attacker to detect the availability of a hidden message in a given signal. The stego quality refers to the level of resemblance between the stego and the cover signal. Robustness, on the other hand, is the ability to tolerate active attacks on stego signals by being able to retrieve the embedded data even after the active attack. The fourth attribute, the hiding capacity, is the ratio of the number of secret bits embedded to the total size of the original hosting signal. Steganography and watermarking are two examples of data hiding techniques [9; 10; 11]. The difference between the techniques is in the final objective to be achieved. In steganography, the intent is to send confidential data between two entities; on the other hand, watermarking techniques are used to provide data integrity or to protect copyright. Therefore, steganography techniques concentrate on the capacity-imperceptibility trade-off, and aim to produce schemes that have the ability to embed a large number of bits while obtaining enhanced quality of the stego signal. Because watermarking techniques aim to provide data integrity or protect the copyright of data, such schemes instead tend to focus more on the robustness attribute. A widely used method in digital steganography involves embedding confidential bits within some selected frequency components of the hosting signal [12; 13; 14]. This method converts the signal to the frequency domain by utilizing a frequency transform technique such as the Discrete Wavelet Transform (DWT), Discrete Cosine Transform (DCT), or Discrete Fourier Transform (DFT). Typically, data are hidden in the high-frequency coefficients, as the human perceptual system is more tolerant of noise in these regions. For instance, edges in a digital image are considered high-frequency components, and noise within these edges is less likely to be detected by the human visual system [5]. The DCT transform is widely recognized as a preferred frequency transform method for steganography due to its strong energy compaction properties, which allow it to efficiently concentrate a signal's energy into a few significant coefficients. This characteristic enables the DCT to express the essential components of a signal with only a few coefficients, leaving a large number of less significant coefficients that can be exploited for embedding secret data with minimal impact on the overall signal quality. By transforming an image from the spatial domain into the frequency domain, the DCT highlights the critical low-frequency components while relegating the high-frequency components to smaller and less perceptible values.