Cyphertext-only attack on the joint-transform-correlator-based optical encryption: experimental demonstration.

Area of Science:

• Optics and Information Security
• Cryptography and Signal Processing

Background:

• Joint transform correlators (JTCs) are optical systems used for pattern recognition and information processing.
• Encryption systems based on JTCs are vulnerable to specific types of attacks.
• Understanding these vulnerabilities is crucial for developing more secure optical encryption methods.

Purpose of the Study:

• To propose a new cyphertext-only attack (COA) targeting joint transform correlator encryption systems.
• To demonstrate the feasibility of recovering plaintext information using the proposed COA.
• To validate the attack through numerical simulations and experimental verification.

Main Methods:

• Development of a cyphertext-only attack (COA) scheme for JTC encryption.
• Calculation of the energy spectral density of the plaintext from the ciphertext.
• Application of phase retrieval algorithms, specifically the hybrid input-output algorithm, for plaintext recovery.

Main Results:

• The proposed COA successfully enables the calculation of plaintext energy spectral density from ciphertext.
• Plaintext information can be recovered by applying phase retrieval techniques.
• Numerical and experimental results confirm the feasibility and effectiveness of the developed attack method.

Conclusions:

• The proposed cyphertext-only attack presents a significant vulnerability in joint transform correlator encryption systems.
• Phase retrieval algorithms are effective tools for recovering plaintext data in this context.
• The findings highlight the need for enhanced security measures in optical encryption systems.