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Study Of Optical Image Encryption Techniques Based On Phase Retrieval Algorithm And Public Key Cryptography

Posted on:2017-02-12Degree:DoctorType:Dissertation
Country:ChinaCandidate:T Y ZhaoFull Text:PDF
GTID:1108330503469911Subject:Physical Electronics
Abstract/Summary:PDF Full Text Request
Asymmetric cryptosystem has the advantage that the encryption key and decryption key are independent of each other, which can well realize the key distribution and management. It is widely used in internet communications as a security technology. Optical asymmetric cryptosystem is a hot topic in the study of optical information security technology and it has become an important part of the optical information security. Therefore, the research of the optical asymmetric cryptography has very important significance. This paper introduces the present researches of the optical asymmetric cryptography and focuses on its development in optical information security; then we systematically and comprehensively analyze the important problems; finally, we set up variety of optical cryptosystem that can meet various practical needs. Specific contents are as follows:Firstly, an optical image encryption system of amplitude- phase hybrid modulation was proposed based on phase retrieval algorithm and RSA public-key algorithm. The system conformed to the communication protocol of the asymmetric cryptosystem. The nonlinear operation of the amplitude-phase hybrid modulation destroyed the linear relationship between the plaintext and ciphertext, which greatly improved the safety of the system. The simulation experiment showed that the proposed encryption system can resist statistical analysis attacks and iterative algorithm attacks.A key distribution scheme was proposed based on the proposed cryptosystem of amplitude- phase hybrid modulation combined with G-S algorithm and RSA public-key algorithm. Which solved the problem that large data secret key was difficult to distribute in optical cryptosystem. Therefore, the key distribution scheme applied to big data key in optical cryptosystem. Computer simulation showed that the proposed scheme can well complete the key distribution task.An image encryption system of changing key was proposed based on the proposed key distribution scheme. Different encryption keys were used in each time encryption process, thus the encryption system conformed to the feature of the one-time pad(OTP) cryptography. The receiver used only the private key and restored message to obtain the plaintext. The simulation results showed the effectiveness of the scheme.The importance of the phase was analyzed and proved. Human biological characteristics had advantage as key,so fingerprint key was introduced to optical cryptosystem. An information verification cryptosystem was proposed based on double random phase encoding system the receiver can use the private key and the fingerprint to decrypt. The results of decryption can determine whether the ciphertext was true and maliciously tampered.Based on the proposed information verification cryptosystem, we proposed that the first random phase encoding was dynamic change. That is, each encryption process produced a new decryption key. Even for the same plaintext, the obtained ciphertext and the decryption keys were different in each encryption process, which implemented that the encryption key and decryption key, the plaintext and ciphertext were independent of each other. Phase modulation technique was used in the cryptosystem, which broken the linear characteristic of the system. The simulation results showed the sensitivity of the fingerprint key.Finally, based on the basic principles of network encrypted card the new research results were obtained in optical image encryption system of phase retrieval algorithm. A single phase modulation of optical devices was proposed, which completed simplification and convenience on the optical image encryption system. The linear relationship between the plaintext and ciphertext was broken by using the password key and the symmetric key, which can resist the existing attacks. Moreover, the system conformed to the feature of the one-time pad and authentication.
Keywords/Search Tags:Image encryption, Phase retrieval algorithm, RSA public-key algorithm, Information security
PDF Full Text Request
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