We show how optical encryption methods based on double random phase keys are vulnerable to an organized attack of the chosen-ciphertext type. The decryption key can be easily obtained by an opponent who has repeated access to either the encryption or decryption machines. However, we have also devised a solution that prevents the attack. Our results cast doubts on the present security of these techniques.
© 2005 Optical Society of America
Arturo Carnicer, Mario Montes-Usategui, Sergio Arcos, and Ignacio Juvells, "Vulnerability to chosen-cyphertext attacks of optical encryption schemes based on double random phase keys," Opt. Lett. 30, 1644-1646 (2005)