# A Finite State Machine-Based Improved Cryptographic Technique
## 2 Literature Survey
### Issues and Challenge  
This suggested effort aims to improve the reliability and security of data transmissions. Steganography is the practice of hiding sensitive data within an apparently innocuous picture. This method protects sensitive information but offers few opportunities for embedding. The quality of the restored cover image likewise suffers when more embedding is applied. Encrypting the steganographic image is one way to boost embedding capacity without sacrificing security. Information that has been encrypted or hidden via steganography may still be vulnerable to channel noise. [17] One possibility is to implement an error-correcting coding scheme. The total cost of computing rises due to the three-step process of steganography, encryption, and error-correcting code required to guarantee the security and dependability of the transmitted data. The updated ME incorporates the concealed data first into a cover photograph. The improved ME was created for maximum embedding effectiveness. Table 1 shows the Comparison of Existing Methodology and their demerits. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Reference** & **Methodology** & **Demerits** \\ \hline \multirow{3}{*}{[18]} & \multirow{3}{*}{DWT-based watermarking algorithm} & The watermark withstands image pre-processing attacks such as median filtering and tolerates noise attacks such as the addition of Gaussian noise and salt-and-pepper noise. \\  & & \\ \cline{1-1}  & Four hashes of IWT coefficients of different subbands & Different parts of the authentication watermark are embedded into different subbands by replacing LSBs. \\ \hline \multirow{3}{*}{[20]} & Proposed technique that shifts the histogram of the difference image & Generated from the original cover image, and modifies pixel values to obtain embedding capacity. \\ \cline{1-1}  & Block-wise embedding of watermark data & Accuracy is less for block-wise detection of forgery. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison Table of Existing Methodology. The suggested Cryptographic Turbo Code is used to encrypt and encode the steganographic image (an embedded cover picture). It is recommended in the Modified Cryptographic Turbo Code (MCTC) that a secret-key FSM should replace the regular FSM, thereby making it a variant of the FSM. With the secret key, a secret-key FSM encrypts the data and corrects transmission problems by shuffling the bits of the input into a new sequence [29]. As an alternative, we suggest using a cryptographic FSM based on elliptic curves to produce random bitstream noise (MCTC-FSM) [24]. The sensitive data is protected on two fronts by the joint efforts of the Modified Minimum Encryption and Minimal Common Transceiver Complexity. This may be achieved by using a steganographic image to covertly conceal the information and then encrypting the whole thing [25]. The cover photo's security and embeddability are both improved by using a steganographic picture for encryption. Recovery quality suffers as embedding capacity rises because more advanced embedding methods change more of the cover image's bits. To get around this issue, the MCTC authors suggest relaying the in-codeword locations of the changed bits through syndrome embedding. Hence, the receiver can decode both the altered bits of the cover image and the hidden data included inside the steganographic picture. Data embedding might be conducted backwards [30]. Due to their reliance on a physical map, current RDH-ED systems can locate the appropriate cover image, but they are unable to insert it. To fill up the discovered knowledge gap, it will be necessary to enhance embedding capabilities via reliable recovery of the cover art. When it comes to correcting bugs, Turbo code is unparalleled. On the downside, it does not safeguard information during transmission. The bit error rate could be decreased by using TC in conjunction with encryption. The present MCTC-FSM is quite effective at detecting and repairing errors.