# A Finite State Machine-Based Improved Cryptographic Technique
## 3 Proposed Methodology
### Finite State Machine with Reverse Data Hiding
\begin{table}
\begin{tabular}{c c} \hline \hline Input: & \(\text{a}=\{a(k),1\leq k\leq K\},\text{We}_{\text{e}}\mathbb{R}_{+}^{U\times V}\) \\ Step 1: & Perform 2-level DTCWT on a to get the wavelet coefficients, and select \(\text{d}_{\text{w}3}\) as \(t\) \\  & \(|\text{d}_{\text{w}1}\text{d}_{\text{w}2}\text{d}_{\text{w}3}\text{a}_{25}|+DTCWT (\text{a})\) \\ Step 2: & Obtain a complex spectrum, applying STFT \\  & \(\text{D}_{\text{m}2}\gets STFT(\text{d}_{\text{w}/2})\) \\ Step 3: & Take the magnitude and phase spectrum \\  & \(\text{M}_{\text{m}3}\gets ABS(\text{D}_{\text{m}3})\text{P}_{\text{m}3 \leq}\) \(ANGLE(\text{D}_{\text{m}3})\) \\ Step 4: & Take the diagonal element \\ Step 5: & Convert the watermark image into a binary watermark image \\  & \(\text{W}=\{\text{w}(u,v),1<=u<=U,1<=v<=V)\}\leftarrow BINARY(WI)\) \\ Step 6: & Transform a binary image to Arnold to transform and reduce the dimension of \\  & \(\text{W}_{1}\gets AE(\text{W})\) \\ Step 7: & \(\text{n}_{1}=\{\text{w}_{1}(p),1\leq p\leq P\}\) \\  & \(\text{n}_{2}\gets BCH(\text{n}_{1})\) \\ Step 8: & Perform 2-level DTCWT on \(w_{2}\) to take the wavelet coefficients and select \(d_{\text{m}3}\) a \\  & \(\left[\text{d}_{\text{m}1}\text{d}_{\text{m}i}\text{d}_{\text{m}i}\text{d}_{ \text{m}i}\right]\leftarrow\text{DCCWT }(\text{w}_{2})\) \\ Step 9: & Obtain a complex spectrum applying STFT \\  & \(\text{D}_{\text{i}3}\leftarrow\text{STFT}(\text{d}_{\text{d}3})\) \\ Step 10: & Take the magnitude and phase spectrum \\  & \(\text{M}_{\text{m}3}\gets ABS(\text{D}_{\text{m}A})\text{P}_{\text{m}3 }+ANGLE(\text{D}_{\text{m}3})\) \\ Input: & Compressed input \\ Step 1: & Obtain a complex spectrum, applying STFT \\  & \(D_{\text{0s}}\gets STFT\left(\widetilde{d}_{\text{w}3}\right)\) \\ Step 2: & Take the magnitude spectrum \\  & \(\widehat{\text{M}}_{\text{13}}\gets ABS\left(\widetilde{\text{D}}_{\text{13 }3}\right)\) \\ Step 3: & Take diagonal element \\  & \(\delta_{\text{o}}-DLAG\left(\widetilde{S}_{\text{i}}\right)\) \\ Step 4: & Perform inverse \(SVD\) operation \\  & \(\widetilde{\text{M}}_{\text{m}i}\leftarrow\text{U}_{\text{im}}\ast\text{S}_{ \text{im}}\ast\text{V}_{\text{im}}^{T}\) \\ Step 5: & Perform inverse STFT operation \\  & \(\text{d}_{\text{im}}\gets ISTFT\left(\widetilde{\text{D}}_{\text{lns}}\right)\) \\ Step 6: & Perform inverse DTCWT operation \\  & \(\widetilde{\text{w}}_{2}\gets IDTCWT(\text{d}_{\text{m}}\text{d}_{\text{m} 2}\text{d}_{\text{im}}\text{)}\) \\ Step 7: & Perform inverse \(BCH\) \\  & \(\widehat{\text{w}}_{1}-IBCH\left(\widetilde{\text{w}}_{2}\right)\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Algorithm of Encryption and Extraction in Proposed Work. are not permitted to do so. The interleaving sequence that is produced by the MCTC is overly sensitive to the fact that the MCTC has a secret key. When the secret key is altered, the interleaving pattern also undergoes considerable revision, which makes it impossible for an unauthorized user to deduce the order in which the inputs will be sent. Elliptic curve cryptography is a typical encryption procedure that offers a high degree of protection to the data that is sent from a sender to a receiver over a public network. This level of protection is provided by the elliptic curve. The elliptic curve equation must be satisfied by a cloud of points for the elliptic curve arithmetic to be performed, since this is the basis for elliptic curve encryption. The positive integers a and b satisfying the curve equation that defines the points on the elliptic curve Ep(a, b) over a finite field Fp is as follows:  
\[y^{2}=(x^{3}+ax+b)\ mod\ p. \tag{15}\]  
The domain parameters, also known as the parameters of the elliptic curve, \(a\), \(b\), and \(p\), describe the point (\(x\), \(y\)) on the elliptic curve in such a manner that both \(x\) and \(y\) are contained inside a finite field, Fp. These domain parameters are also known as the elliptic curve parameters. This is the lowest positive integer that might possibly fulfil the requirements of the condition.