Known techniques of breaking Double Random Phase Encoding (DRPE), which bypass the resource-intensive brute-force method, require at least two conditions: the attacker knows the encryption algorithm; there is an access to the pairs of source and encoded images. Our numerical results show that for the accurate recovery by numerical brute-force attack, someone needs only some a priori information about the source images, which can be quite general. From the results of our numerical experiments with optical data encryption DRPE with digital holography, we have proposed four simple criteria for guaranteed and accurate data recovery. These criteria can be applied, if the grayscale, binary (including QR-codes) or color images are used as a source.
Nalegaev, S. S., & Petrov, N. V. (2015). Simple Criteria to Determine the Set of Key Parameters of the DRPE Method by a Brute-force Attack. In Physics Procedia (Vol. 73, pp. 281–286). Elsevier B.V. https://doi.org/10.1016/j.phpro.2015.09.137