title: Vulnerability to chosen-cyphertext attacks of optical encryption schemes based on double random phase keys.
abstract: 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.
authors.affiliation: Universitat de Barcelona, Departament de Física Aplicada i Optica, Diagonal 647, 08028 Barcelona, Spain. artur.carnicer@ub.edu
authors.forename: Arturo
authors.initials: A
authors.lastname: Carnicer
authors.forename: Mario
authors.initials: M
authors.lastname: Montes-Usategui
authors.forename: Sergio
authors.initials: S
authors.lastname: Arcos
authors.forename: Ignacio
authors.initials: I
authors.lastname: Juvells