Asymmetric encryption method in 4f system based on interference

With the rapid development of computer network technology, information security has attracted increasing attention. Due to the characteristics of multi-dimensional operation and parallel processing capability, optical image encryption techniques have been receiving more and more attention. Since the well-known double random phase encoding technique was proposed, many other methods based on optical information processing means such as the use of optical transform, interference, and polarized light encoding, have been proposed for optical image encryption. However, recent researches have demonstrated that traditional optical encryption techniques are symmetric cryptosystems, in which decryption keys are identical to encryption keys and they have been found to be vulnerable to different types of attacks, such as known plaintext and chosen plaintext attacks. To overcome this shortcoming, asymmetric cryptosystems based on nonlinear phase-truncation techniques and phase retrieval algorithm have been proposed. Asymmetric cryptosystem is a cryptographic system in which encryption keys are different from decryption keys. The encryption keys are used as public keys which are disseminated widely, and the decryption keys are used as private keys which are known only to the authorized users. So, asymmetric cryptosystem can offer a higher-level security than symmetric cryptosystem. However, asymmetric cryptosystems based on phase retrieval algorithms require a lot of computational time, and asymmetric cryptosystems based on phase-truncated Fourier transforms have been found to be vulnerable to special attack. Therefore, in this paper, a novel asymmetric image encryption method is proposed by using the gyrator transform and vector operation. The original image is encrypted into two phase masks with vector operation. One is a random phase mask and the other is a phase mask related to the original image. In the encryption process, the random phase mask is used as a phase key and the other phase mask is transformed by gyrator transform. The transform result is performed by Fourier transform after being modulated by a phase distribution. The ciphertext is the amplitude of the above result. Compared with previous encryption schemes, the suggested method has two advantages. Firstly, we have proposed a new asymmetric encryption method based on the gyrator transform and vector operation. The decryption process is different from the encryption process. The gyrator transform and Fourier transform are used in the encryption process, while only the inverse operation of Fourier transform is employed in the decryption process. In addition, the decryption keys produced in the encryption process are different from the encryption keys. Therefore, the proposed scheme has high resistance against the conventional attacks. Secondly, the encrypted result is real-valued, which is convenient for display, transmission and storage.Numerical simulations illustrate the feasibility and effectiveness of the proposed encryption scheme.

The RC-5 algorithm is an algorithm with the encryption method using the symmetric method and processing in the form of a cipher block, the same keywords are used for the encryption and decryption processes. The testing and analysis phase consists of a). Testing the execution time of the key generation process (set up key) b). Testing the success of the encryption and decryption process on the client-server integration method c). Testing the success of the encryption and decryption process using the file operation method d). Comparison of overhead/file size before and after passing through the system. The testing phase and execution time analysis are carried out when using the file operation method where the test will be divided into 3 parts, namely the execution time for the key setup process, the encryption process, and the decryption process. Testing the success of the encryption and decryption process on the client-server integration method is divided into 2 parts, namely testing the encryption process and the decryption process. In testing the encryption process, the characters that will be sent to the server will be encrypted first with a key to becoming a ciphertext in the form of integer data. The test results obtained are 1). The execution time for key generation (set up key) is very fast, around 9-10 ns. 2). In the encryption and decryption process, the execution time depends on the size of the plaintext file. The larger the plaintext file size, the longer the execution time. Where for a file with a size of 1 kb requires an execution time of 50.6 ms in the encryption process. 3). There is no difference between the size of the file before entering encryption and after decryption. Where for files with a size of 500 bytes before entering the encryption process, a file of 500 bytes will be generated from the decryption process.

Fully phase multiple information encoding based on superposition of two beams and Fresnel-transform domain

Security of sensitive information at the time of transmission over public channels is one of the critical issues in digital society. The DNA-based cryptography technique is a new paradigm in the cryptography field that is used to protect data during transmission. In this paper we introduce the asymmetric DNA cryptography technique for encrypting and decrypting plain-texts. This technique is based on the concept of data dependency, dynamic encoding and asymmetric cryptosystem (i.e. RSA algorithm). The asymmetric cryptosystem is used solely to initiate the encryption and decryption processes that are completely conducted using DNA computing. The basic idea is to create a dynamic DNA table based on the plaintext, using multi-level security, data dependency and generating 14 dynamic round keys. The proposed technique is implemented using the JAVA platform and its efficiency is examined in terms of avalanche property. The evaluation process proves that the proposed technique outperforms the RSA algorithm in terms of avalanche property.

During the last five years, spiking neural P (SN P) systems have attracted a lot of attention in the field of cryptography since these systems can more efficiently support advanced and complex cryptographic algorithms due to their high computational capabilities. Specifically, these systems can be seen as a potential solution to efficiently performing asymmetric algorithms, which are more demanding than symmetric systems. This factor becomes critical, especially in resource-constrained single-board computer systems, since many of these systems are currently used to ensure the security of IoT applications in portable systems. In this work, we present for the first time the implementation of an asymmetric encryption algorithm called ElGamal based on spiking neural P systems and their cutting-edge variants. The proposed design involves the encryption and decryption processes. Specifically, we propose the design of a neural network to efficiently perform the extended Euclidean algorithm used in the decryption task. Here, we exert major efforts to create a compact and high-performance circuit to perform the extended Euclidean algorithm since the calculation of this algorithm is the most demanding when the decryption process is required. Finally, we perform several tests to show the computational capabilities of our proposal in comparison to conventional implementations on single-board computer systems. Our results show that the proposed encryption/decryption scheme potentially allows its use to ensure confidentiality, data integrity, and secure authentication, among other applications for resource-constrained embedded systems.

One of the main elements of the integrated information security system is the subsystem of access’s control to information resources. Recently, more attention is attracted by biometrics as one of the newest information technologies that use the unique characteristics of object identification and verification. Therefore, the question of the protection of information resources from unauthorized administrative actions and access by unauthorized persons or programs to computer data is important.Relevant is the preservation of confidentiality of information processed or stored in computer systems. External influences generally oppose using a variety of software and hardware protection methods. The content of the methods of the protective transformations is that the information stored in the system and is transmitted by communication channels, is turns into a cryptogram — a closed (encrypted) text or graphic image documents. The basis for the encryption is based on two elements: a cryptographic algorithm and key. The security of generic algorithms is determined by the key length. In asymmetric algorithms, the encryption and decryption can be performed with different keys. Such algorithms require significantly more computation time, but do not create problems during key distribution. The most promi-sing data protection systems today are considered an asymmetric system with a public key. The last deca-de a great attention of scientists in the field of information security pay biometric. A biometric system can operate in modes of verification and identification. All of these approaches protect the information easy enough to implement in the time-logic environment, making all the settings required for message transform on the time-logic functions.The possibility of cyclic encoding and the rules for constructing key asymmetric crypto algorithm on the basis of the identification time-logic functions, which contain all the important characteristics of transmitted messages, is analyzed. Available for the formal description of this encoding and the rules of construction keys used in the representation of time-logic functions in the form of polynomials.

The science and art that is used to take care of message security by encoding messages into obfuscated forms is called cryptography. In cryptography, there are two types of algorithms, which are symmetric and asymmetric algorithms. The RC4+ algorithm and the Variably Modified Permutation Composition (VMPC) algorithm are examples of symmetric algorithms in the form of stream ciphers where the process of encryption and decryption is done by using the same key. To achieve the security objectives, these two algorithms are then used and applied into the three-pass protocol scheme. The three-pass protocol is a cryptographic scheme for sending and receiving messages that allows one party to securely send messages to a second party without the need to exchange the keys. As a result, this research succeeded in securing text file with (*.docx) dan (*.pdf) and can restore the data back as before by combining the RC4+ algorithm and the Variably Modified Permutation Composition (VMPC) algorithm in the three-pass protocol scheme. The theoretical complexity of these two algorithms is θ(n) both for encryption and decryption. The actual running time is directly proportional to the length of the character of a file.

A new LabVIEW simulation design was applied to provide a comparison study among several types of the most common symmetric and asymmetric encryption algorithms. Also, the comparison with advanced encryption package program was made. The results showed that the new LabVIEW simulation design had advantages in several points, where the evaluated time required for the encryption and decryption processes will be lesser than it values using advanced encryption package program.In this work, the symmetric encryption algorithms were used: AES (Advanced Encryption Standard), DES (Data Encryption Standard), 3DES (Triple Data Encryption Standard) and RC2 (Rivest Cipher) algorithms, while the asymmetric encryption algorithm used was the RSA (Rivest-Shamir-Aldeman) algorithm. The comparison had been achieved using different sizes of text files with different key sizes. The final results proved that the LabVIEW simulation design is better than the Advanced Encryption Package because it increased the algorithm’s performance by 65% in terms of speed and throughput, and for the algorithms’ comparison, the final results showed the effectiveness of AES algorithm over the other algorithms in terms of speed and throughput for the encryption and decryption processes.

In this paper, fault detection scheme is introduced to improve the security and reliability of the NTRU in realistic environments, such as operating over a network. As the NTRU will be working in real networks, which have their own set of transient errors, handling such errors in analyzing the NTRU becomes a must. A single transient error occurring during the NTRU encryption (or decryption) process will likely result in a large number of errors in the encrypted/decrypted data. Such faults must be detected before sending data to avoid the transmission and use of erroneous data. Concurrent fault detection is important not only to protect the encryption/decryption process from random faults, but it will also protect the decryption circuitry from an attacker who may maliciously inject faults in order to find the secret key. We first describe the effects that faults may have on NTRU security while operating over a network by analyzing the propagation of such faults to the outputs. We then present two fault detection schemes: The first is a redundancy-based scheme while the second uses an error detection code. The latter present fault detection schemes by using an error detecting code, using one parity bit. We will add the parity bits to the polynomials and disable the device output when any of these parity checks are violated. This fault detection scheme has more than 99% coverage fault detection in the encryption process and in the first part in the decryption process. In the second part in the decryptionprocess, it has more than 67 % coverage fault detection. We can increase this ratio to high fault detection by adjusting the choices of the parameters of the NTRU network security system.

The need for strong data security while preserving maximum speed is becoming more and more important as cloud computing continues to change the digital world. Even if they are efficient, conventional cryptographic techniques sometimes give off security for efficiency. To overcome these difficulties, hybrid cryptographic algorithms, an emerging paradigm, combine the benefits of symmetric and asymmetric encryption methods. This article presents a thorough analysis of the design, use, and ramifications of hybrid cryptographic algorithms used in cloud networks. The first step of the research is to establish the shortcomings of current cryptographic techniques and the necessity of hybrid strategies. The work focuses on creating unique algorithms that take use of the strength of symmetric encryption for data secrecy and the security of asymmetric encryption for key exchange, drawing conclusions from the convergence of encryption paradigms. The project investigates the applicability and feasibility of these algorithms in real-world contexts by a methodical implementation within cloud networks.

Cryptographic Primitives that Resist Backdooring and Subversion

광을 이용하여 암호화를 하는 경우는 위조 및 복제의 방지를 위하여 세기성분보다는 위상성분을 이용하여 주로 암호화를 하고 있다. 그러나 위상정보를 검출할 수 있는 장비가 개발된다면 정보를 유출 당할 수 있는 위험이 있다. 이러한 위험을 줄이기 위해 본 논문에서는 가상 위상영상을 이용하고 또한 정보를 다수가 공유할 수 있도록 시각 암호화(visual cryptography) 방법을 이용하여 정보를 보다 안전하게 보관하고 공유하는 시스템을 제안하였다. We propose an encryption method using visual cryptography and virtual phase images. In the encryption process, the original image is shared by virtual images and the decryption key image. We multiply the virtual phase images with each complex image, which has the constant value of its sum after performing the phase modulation of the virtual images and the decryption key. The encryption cards are made by Fourier transforming the multiplied images. It is possible to protect information about the original image because the cards do not have any information from the original image. To reconstruct the original image, all the encryption cards are placed on each path of a Mach-Zehnder interferometer and then the lights passing through them are summed. Since the summed image is inverse Fourier transformed by a Fourier lens, the phase image is multiplied with the decryption key and the output image is obtained in the form of intensity on the CCD plane. Computer simulations show a good performance of the pro-posed optical security system.

With advances in technology like today, documents can be sent digitally via the internet media. An important problem faced in sending digital documents is that often documents sent can be accessed by parties who do not have the authority over these documents. The solution to this problem is to secure digital documents before transmission. One of the methods to secure data is cryptography. Cryptography with asymmetric keys is the strongest data security technique to use. One of the most widely used asymmetric cryptography is the RSA (Rivest-Shamir-Adleman) algorithm. The type of document that is encrypted is the most commonly attached document when sent e-mails. The document types are .docx, .pptx, .xlsx, .pdf, .jpg and .mp4. In the encryption process, a public key and a private key will be generated which can be sent separately by sending encrypted digital documents. The decryption process for digital documents is carried out from the receiving end of the document using a private key generated in the encryption process. The encryption result has a size larger than the original file size because it has been encoded in another form according to the RSA algorithm. The longer and bigger the input size, the longer it will take required for encryption.

Most of the existing selective encryption schemes are based on image processing and cannot be realized by optical structures, so their practicality is limited. Combining the optical design, a local hybrid optical encryption system based on double random phase encoding is proposed. The system proposed in this paper possesses a common aperture and dual optical path structure, which is widely used in optical design and can effectively improve the practicality of optical encryption system. First, important information and non-important information in the original image are separated by a selective beam splitter. Then light waves carrying important information enter into the 4<i>f</i> system for encryption, and light waves carrying non-important information enter into the diffraction system for encryption. Finally, part of the diffraction system ciphertext is replaced with 4<i>f</i> system ciphertext to obtain the final encrypted image. Decryption is the reverse process of encryption. First, the 4<i>f</i> system ciphertext is cut out from the final ciphertext. Then the 4<i>f</i> system ciphertext is used to restore the information replaced in the diffraction system ciphertext, thereby obtaining the complete diffraction system ciphertext. Finally, the two ciphertexts go through the reverse process of their respective systems to complete the decryption. By comparing the statistical characteristics and mean square error of the original image and the encrypted image, the effectiveness of the proposed system's encryption process is proved. By analyzing the peak signal-to-noise ratio of the original image and the decrypted image, the effectiveness of the proposed system's decryption process is proved. The sensitivity of each key of the system is analyzed to prove the security of the system. Especially the system is highly sensitive to selective encryption key, which proves the effectiveness and security of the proposed system for selective encryption. Through simulation, it is verified that the proposed system is very resistant to diffraction attacks. Even if he can obtain all the diffraction keys, the attacker still cannot obtain the selectively encrypted information. Finally, through simulation, it is verified that the proposed system has good noise resistance and crop resistance, and high robustness as well. The proposed system can realize the selective encryption through optical structure, which is safe, effective and highly robust, and thus improving the practicality of selective optical encryption system.

Fault-based side channel cryptanalysis is a very effective cryptanalytic technique against symmetric and asymmetric encryption algorithms. Attackers can induce errors during the encryption or decryption process in order to collect information concerning secret information, such as cryptographic keys. In recent years, the security of the Advanced Encryption Standard (AES) against fault analysis attacks has received considerable attention. While FPGAs are becoming increasingly popular for cryptographic applications, there are only few articles that assess their vulnerability to such attacks only a small number of experiments can be found in the literature on the actual possibility to apply such attacks to FPGAs. The purpose of this paper is to describe a practical and successful implementation of the attack and to provide strong evidence that fault induction is a serious threat against realizations of the AESon FPGAs without effective countermeasure. The results obtained in this paper can serve to design a more secure FPGA implementation of the AES.