List of Articles Cryptography

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  1 - A Study On Visual Cryptography and Providing a Proposed Method for Color Images Cryptography
  shahriyar mohammadi نغمه محمدی
  Visual cryptography is a method that makes use of the characteristics of human vision and it requires neither the knowledge of cryptography nor the complex calculations. This method was first proposed by Naor and Shamir, its implementation is simple, it has been extende More

  Visual cryptography is a method that makes use of the characteristics of human vision and it requires neither the knowledge of cryptography nor the complex calculations. This method was first proposed by Naor and Shamir, its implementation is simple, it has been extended to an secrect sharing (k, n) in which n shares are made from the image and they are distributed among n participants. Moreover, the image can be retrieved with k shares and their assembling onto each other; however, the image is not retrievable with k-1 shares. Colors are represented using a combination of reflected lights from objects in the subtractive model. A wide range of colors is made with the mixture of cyan (C), magenta (M) and yellow (Y) and the combination of blue (B), red (R) and green (G) results in black in this model and also, the combination of these colors with white creates the same colors. This paper presents a visual cryptography proposal for colored images that divides a colored image into some shares after converting it to halftone images based on white and black visual cryptography and their rules are in accordance with the subtractive model of colors. Manuscript profile
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  2 - A New Finite Field Multiplication Algorithm to Improve Elliptic Curve Cryptosystem Implementations
  Abdalhossein Rezai Parviz Keshavarzi
  10.7508/jist.2013.02.006
  This paper presents a new and efficient implementation approach for the elliptic curve cryptosystem (ECC) based on a novel finite field multiplication in GF(2m) and an efficient scalar multiplication algorithm. This new finite field multiplication algorithm performs zer More

  This paper presents a new and efficient implementation approach for the elliptic curve cryptosystem (ECC) based on a novel finite field multiplication in GF(2m) and an efficient scalar multiplication algorithm. This new finite field multiplication algorithm performs zero chain multiplication and required additions in only one clock cycle instead of several clock cycles. Using modified (limited number of shifts) Barrel shifter; the partial result is also shifted in one clock cycle instead of several clock cycles. Both the canonical recoding technique and the sliding window method are applied to the multiplier to reduce the average number of required clock cycles. In the scalar multiplication algorithm of the proposed implementation approach, the point addition and point doubling operations are computed in parallel. The sliding window method and the signed-digit representation are also used to reduce the average number of point operations. Based on our analysis, the computation cost (the average number of required clock cycles) is effectively reduced in both the proposed finite field multiplication algorithm and the proposed implementation approach of ECC in comparison with other ECC finite field multiplication algorithms and implementation approaches. Manuscript profile
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  3 - Security Enhancement of Wireless Sensor Networks: A Hybrid Efficient Encryption Algorithm Approach
  Omid Mahdi Ebadati Farshad Eshghi Amin Zamani
  10.7508/jist.2018.03.007
  Wireless sensor networks are new technologies that are used for various purposes such as environmental monitoring, home security, industrial process monitoring, healthcare programs and etc. Wireless sensor networks are vulnerable to various attacks. Cryptography is one More

  Wireless sensor networks are new technologies that are used for various purposes such as environmental monitoring, home security, industrial process monitoring, healthcare programs and etc. Wireless sensor networks are vulnerable to various attacks. Cryptography is one of the methods for secure transmission of information between sensors in wireless sensor networks. A complete and secure encryption system must establish three principles of confidentiality, authentication and integrity. An encryption algorithm alone cannot provide all the principles of encryption. A hybrid encryption algorithm, consisting of symmetric and asymmetric encryption algorithms, provides complete security for a cryptographic system. The papers presented in this area over the last few years, and a new secure algorithm present with regard to the limitations of wireless sensor networks, which establishes three principles of cryptography. The details of the algorithm and basic concepts are presented in such a way that the algorithm can be operational and showed a very high efficiency in compare to the current proposed methods. Manuscript profile
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  4 - Design and Analysis of Low Frequency Communication Multipath Channel to Safe Transmitting Speech Signal in Persian Gulf
  H. Bakhshi H. Shahbazi
  One of the important applications of underwater communication is speech transmission between two divers or between divers and ship or submarine. This paper describes a project designed to investigate and demonstrate underwater communication system in Persian Gulf for sp More

  One of the important applications of underwater communication is speech transmission between two divers or between divers and ship or submarine. This paper describes a project designed to investigate and demonstrate underwater communication system in Persian Gulf for speech transmission in a real channel. At first, transmitter is designed, then channel with real data is simulated by neural network and at last receiver is designed. Transmitted data is speech signal that for more secure transmission and low frequency bandwidth, a cryptography algorithm and speech coding algorithm is applied in transmitter. Quadrature phase shift keying (QPSK) signaling is employed to make efficient use of the available channel bandwidth. In the receiver, linear equalizer and decision feedback equalizer (DFE) are tested and the best scheme is applied. Also, ray tracing method is used for simulation of sound waves propagation in Persian Gulf underwater communication channel. Manuscript profile
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  5 - Improved Semi-Quantum Direct Communication Protocol
  Z. rashidi M. hooshmand
  Unlike classical cryptography, where security is based on computational complexity, quantum cryptography has unconditional security, which is based on physical constraints. So far, the semi-quantum version of many of the problems of secure quantum communication protocol More

  Unlike classical cryptography, where security is based on computational complexity, quantum cryptography has unconditional security, which is based on physical constraints. So far, the semi-quantum version of many of the problems of secure quantum communication protocols has been proposed. In this study, we examined semi-quantum protocols that allow users to access a secret message directly without distributing the key. An important factor used to analyze the performance of secure quantum direct communication protocols is efficiency. In this study, the proposed semi-quantum secure communication protocol against various quantum attacks has been investigated. In the proposed scheme for decoding the confidential message by the receiver, a sequence of single photons is required, which is first generated by the controller. The proposed protocol has a yield of 50%, which is higher than the previous protocol, which has a yield of 66.6%. Manuscript profile
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  6 - Maintaining Confidentiality and Integrity of Data and Preventing Unauthorized Access to DICOM Medical Images
  Mohammad Soltani Hassan Shakeri Mahboobeh Houshmand
  With the development of telecommunication and communication technologies, especially wireless communications, information cryptography is one of the communication necessities. Today, cryptographic algorithms are used to increase security and prevent DICOM medical images More

  With the development of telecommunication and communication technologies, especially wireless communications, information cryptography is one of the communication necessities. Today, cryptographic algorithms are used to increase security and prevent DICOM medical images from unauthorized access. It should be noted that changes in DICOM medical images will cause the doctor to misdiagnose the patient's treatment process. In this paper, a type of hybrid cryptographic algorithms is designed. In the proposed algorithm, DNA encryption algorithm is used to encrypt DICOM images and patient biometric information such as fingerprint or iris image is used to make digital signature and validate DICOM medical images. The designed encryption algorithm is resistant to brute force attacks and the entropy of the encrypted DICOM images is above 7.99. Manuscript profile