Known-plaintext attack on a joint transform correlator encrypting system

Abstract

We demonstrate in this Letter that a joint transform correlator shows vulnerability to known-plaintext attacks. An unauthorized user, who intercepts both an object and its encrypted version, can obtain the security key code mask. In this contribution, we conduct a hybrid heuristic attack scheme merge to a Gerchberg-Saxton routine to estimate the encrypting key to decode different ciphertexts encrypted with that same key. We also analyze the success of this attack for different pairs of plaintext-ciphertext used to get the encrypting code. We present simulation results for the decrypting procedure to demonstrate the validity of our analysis.

Nonlinear optical security system based on a joint transform correlator in the Fresnel domain

“…Section 2 describes the proposed nonlinear JTCbased encryption system in the FrD and presents some numerical experiments to illustrate the proposal. Section 3 specifies the system resistance against CPA [26] and KPA [27]. The results presented and discussed in the paper lead us to outline the conclusions in Section 4.…”

“…This weakness is due to the linear property of the DRPE scheme [24]. The DRPE implemented by means of a JTC is also vulnerable to CPA [26] and KPA [27]. Finally, the optical DRPE in the FrD proposed in [3][4][5] is also vulnerable to plaintext attacks [28,29].…”

“…The nonlinear JTCbased encryption system in the FrD [31] is mathematically described and further investigated in this paper with the introduction of a general random complex mask (RCM), the use of different probability density functions to generate the random codes, and the evaluation of the system resistance to cryptanalysis. As we will show in the following sections, the nonlinearity introduced in the JFPD and other features of the optical setup, make the system more resistant to CPA [26] and KPA [27]. We also use a RCM as the key of the security system, where both the modulus and phase functions of the RCM are of random magnitudes.…”

Optical encryption and QR codes: Secure and noise-free information retrieval

“…2, we sequentially show (a) the input object, (b) the encrypted object, (c) the result of decrypting but using an invalid key, and (d) the correct recovered object observing the inherent speckle noise all over the image. Obviously, the speckle noise is unavoidable when employing optical encryption with DRPE under any architecture, domain, or protocol [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. …”

“…Validation and watermarking were also branches derived from the encrypting proposals [15,16]. Besides, the resistance to hacker attacks was analyzed to look for weaknesses and to reinforce the encrypting strength [17][18][19]. Common to these proposals are the recognized capabilities of protecting information the optics brings, as alternatives to previous well established methodologies.…”