Cipher

About: Cipher is a research topic. Over the lifetime, 9409 publications have been published within this topic receiving 110309 citations. The topic is also known as: cypher & cryptographic algorithm.

Design of a robust cryptosystem algorithm for non-invertible matrices based on hill cipher

Abstract: Summary Information security is an important issue. Hill Cipher is one of the most famous symmetric cryptosystem that can be used to protect information from unauthorized access.Hill cipher is a polygraph substitution cipher based on linear algebra. Invented by Lester S. Hill in 1929, it was the first polygraph cipher which was practical to operate on more than three symbols at once, Hill Cipher has many advantages in data encryption. First, it is resistant to the frequency letter analysis. It's also very simple since it uses matrix multiplication. Finally, it has high speed and high throughput [1,13,14], However, noninvertible key matrix over is the main disadvantage of Hill Cipher, because few of the matrices have inverses over . This means that the encrypted text can't be decrypted [2]. This paper suggests a new technique in Hill Cipher algorithm to overcome its major problemnoninvertible key matrix. also our paper suggest enhancement the security of Hill Cipher against known plaintext attack because all steps in Hill Cipher depend on linear algebra calculation This is possible by using public key idea and key generating depending on various options and without linear algebra steps. Therefore, it will be difficult for the attacker to get the key. Finally, our paper will present a proper solution for the problem of sending secret key ( ) for the first time. Our idea is using a public key public ( ) that doesn't sent but generated in the encryption and decryption sides.

Image Encryption Using Dynamic S-Box Substitution in the Wavelet Domain

Abstract: A number of image encryption techniques have been proposed in recent years. These techniques use either spatial or transform domain image processing. A major challenge when designing an image encryption scheme is to conceal the pixel of the input image, especially when the image has a low texture region. Another problem is the encryption computational time. In this paper, these two issues are addressed. As the use of a single substitution box (S-box) to encrypt digital images does not work well for greater as well as a lower number of gray levels. To solve this problem, a new substitution technique using multiple S-boxes with dynamic substitution is proposed. In the second part of this paper, the proposed discrete wavelet transform based scheme is employed to reduce the encryption computational time. A number of parameters like correlation, entropy, energy, contrast, homogeneity, MSE and PSNR are used to analyze the quality of cipher images.

ASIC Hardware Performance

Abstract: This chapter presents detailed hardware implementation results and performance metrics for the eSTREAM candidate stream ciphers remaining in the Phase 3 hardware profile. Performance assessment has been made in accordance with the eSTREAM hardware testing framework in terms of power, area and speed. An attempt has been made to quantify the flexibility and scalability dimensions of performance. The results are presented in tabular and graphical format together with summarising the utility of the candidates against two notional applications: one for 10Mbps wireless network and a second for 100kHz RFID. Where applicable to a particular cipher, guidance on any limitations on the choice of key or IV is given. The chapter concludes with a summary of the performance of each of the candidates and some general guidance for future low resource hardware stream cipher development.

Memory encryption for digital video

Abstract: A method for protecting data between a circuit and a memory is disclosed. The method generally includes the steps of (A) generating a particular address among a plurality of addresses for accessing a particular area among a plurality of areas in the memory, (B) determining a particular key among a plurality of keys associated with the particular area, (C) generating a cipher stream from both the particular address and the particular key and (D) modifying a data item with the cipher stream such that the data item is encrypted during a transfer between the circuit and the memory.

Fast query over encrypted character data in database

Abstract: Cryptographic support is an important dimension of securing sensitive data in databases. But this usually implies that one have to sacrifice performance for security. In this paper, we describe an novel cryptographic schemes for the problem of searching on encrypted character data and provide analysis of security for the resulting cryptographic systems.When the character data are stored in the form of cipher, we store not only the encrypted character data, but also characteristic values of character data as an additional field in database.When querying the encrypted character data,we apply the principle of two-phase query. Firstly, it implements a coarse query over encrypted data in order to filter part records not related to querying conditions. Secondly, it decrypts the rest records and implements a refined query over them. Results of a set of experiments validate the functionality and usability of this approach.