Algorithm 2. CI generation, WM, and EHR data extraction and decryption

Input: Stego Image (SI) M × N, keys as initial conditions and control variables

Output: Cover Image (CI) of size M × N, WM, EHR

BEGIN $s1\prime , s2\prime , s3\prime , s4\prime$ ← key as an initial condition for hyperchaos a′, b′, e′, t’, l1′, l2′, l3′ ← control parameters for hyperchaos for n1 = 2: x12 $\dot{s{\prime }_{1 \left(\mathrm{n}1+1\right)}}$ = $a\prime \left(s_2\prime - s_1\prime \right)+ l_1\prime s_4\prime$ $\dot{s{\prime }_{2\left(\mathrm{n}1+1\right)}}= e\prime s_1\prime - s_1\prime s_3\prime + l_2\prime s_4\prime$ $\dot{s{\prime }_{3\left(\mathrm{n}1+1\right)}}$ = −b$\prime s_3\prime - s_1\prime s_2\prime + l_3\prime s_4\prime$ $\dot{s{\prime }_{4\left(\mathrm{n}1+1\right)}}=- t\prime s_1\prime$ end for Obtain PRN sequence Extricate the LSB bits from the non-seed pixels of the SI to form the encrypted WM and encrypted EHR data bit vectors     for rounds  ←  1: length (extracted data vector) Original data vector = extracted data vector ⊕ k End Obtain the WM and EHR from this data vector Reshape the original WM to check if it has tampered Reconstruct the CI using the seed pixels. END