Algorithm 1: Pseudocode of Emb()

Input: a cover text (CM), a secret message (SM), a secret key (K) Output: a carrier text message or stego-object (CMHM) which consists of CM and HM 1. SM← Secret Message (e.g., confidential information such as password, banking credentials, etc.); 2. CM← Cover Message (e.g., an innocent text message such as prank, joke, etc.); 3. K← Secret Key (e.g., a symmetric or asymmetric key algorithm such as One-Time-Pad, AES, DES, etc.); 4. for each $c_i\in SM=\left\{c_1,c_2,\dots ,c_n\right\}$ do 5. SMbits← SMbits + Convert each $SM[c_i]$ to a 8-bit string based on the ASCII Code; 6. end for 7. Encrypted _SMbits← Encrypts the SMbits based on K using a special encryption function; 8. HM← Convert the Encrypted_SMbits to invisible symbols such as space between words, text color, etc.; 9. CMHM← Embed the HM into the CM, where the attacks may not detect/remove it easily; 10. Return CMHM;