1. Sarkar, T., Selvakumar, K., Motiei, L. & Margulies, D. Message in a molecule. Nat. Commun. 7, 11374 (2016).
2. Challita, K. & Farhat, H. Combining steganography and cryptography: new directions. Int. J. New Comput. Archit. Their Appl. 1, 199–208 (2011).
3. Raphael, A. J. & Sundaram, V. Cryptography and steganography—a survey. Int. J. Comput. Technol. Appl. 2, 626–630 (2011).
4. Dooley, J. F. Review of prisoners, lovers, & spies by Kristie Macrakis. Cryptologia 40, 107–112 (2016).
5. Sun, H. et al. Smart responsive phosphorescent materials for data recording and security protection. Nat. Commun. 5, 3601 (2014).