Securing Digital Holographic Complex Information using Double Random Phase Fresnel Plane Encoding and Diffie-Hellman Key Exchange

Background/Objectives: Using digital holography, one can detect and retrieve 3D information as digital complex images. Such information from digital holography can be secured by the use of virtual optics encryption algorithms. Methods/Statistical Analysis: The paper demonstrates a new method for securing digital holographic information using optical encryption algorithms implemented in digital domain. A double random phase encoding in input plane and Fresnel plane is implemented to secure the retrieved digital holographic data. The Diffie-Hellman key exchange implemented along with this scheme enhances the security level. The Diffie-Hellman secret key has been generated using the sender’s private key and receiver’s public key. Findings: The Diffie-Hellman key exchange gives another protective layer to the double random phase plane encrypted information. An unauthentic user attempts to decode the information with incorrect encoding parameters such as symmetric secret key, wavelength and the propagation distance would fail to retrieve the original information. The Signal to Noise Ratio (SNR) is very low and the Mean Square Error (MSE) is very high when an attacker user uses any one of the wrong encoding parameters. This clearly demonstrates that the unauthenticated user either gets wrongly decrypted information or the original information is totally lost. Conclusion/Improvements: The effectiveness and advantages of the proposed method are demonstrated by simulation results. The proposed method can provide a greater confidentiality and authenticity of the digital information because the system incorporates two layers of protection.