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.

A security enhanced robust audio steganography algorithm for image hiding using sample comparison in discrete wavelet transform domain and RSA encryption

Abstract: Steganography is the technique of hiding any secret information like text, image or video behind a cover file. Audio steganography is one of the widespread data hiding techniques that embeds secret data in audio signals. The secret data is hidden in a way that unauthorized people are not aware of the existence of the embedded data and without changing the quality of the audio signal (cover audio). Data hiding in audio signals has various applications such as protection of copyrighted audio signals, secret communication, hiding data that may influence the security and safety of governments and personnel. This paper proposes an efficient steganography scheme based on sample comparison in Discrete Wavelet Transform (DWT) domainwhere the cover audio is decomposed into several multi sub-bands, and then selected coefficients of details are changed by a threshold value depending on the embedding cipher image bit. This approach employs an original image component to perform RSA encryption on it, then cipher bits are embedded in the details components of the audio signal according to a predetermined threshold value. The performance of the algorithm has been estimated extensively against attacks, and simulation results are presented to prove the robustness of the proposed algorithm.

Verifiable Delegated Set Intersection Operations on Outsourced Encrypted Data

Abstract: We initiate the study of the following problem: Suppose Alice and Bob would like to outsource their encrypted private data sets to the cloud, and they also want to conduct the set intersection operation on their plaintext data sets. The straightforward solution for them is to download their outsourced cipher texts, decrypt the cipher texts locally, and then execute a commodity two-party set intersection protocol. Unfortunately, this solution is not practical. We therefore motivate and introduce the novel notion of Verifiable Delegated Set Intersection on outsourced encrypted data (VDSI). The basic idea is to delegate the set intersection operation to the cloud, while (i) not giving the decryption capability to the cloud, and (ii) being able to hold the misbehaving cloud accountable. We formalize security properties of VDSI and present a construction. In our solution, the computational and communication costs on the users are linear to the size of the intersection set, meaning that the efficiency is optimal up to a constant factor.

Key Recovery from State Information of Sprout: Application to Cryptanalysis and Fault Attack.

Abstract: Design of secure light-weight stream ciphers is an important area in cryptographic hardware & embedded systems and a very recent design by Armknecht and Mikhalev (FSE 2015) has received serious attention that uses shorter internal state and still claims to resist the time-memory-data-tradeoff (TMDTO) attacks. An instantiation of this design paradigm is the stream cipher named Sprout with 80-bit secret key. In this paper we cryptanalyze the cipher and refute various claims. The designers claim that the secret key of Sprout can not be recovered efficiently from the complete state information using a guess and determine attack. However, in this paper, we show that it is possible with a few hundred bits in practical time. More importantly, from around 850 key-stream bits, complete knowledge of NFSR (40 bits) and a partial knowledge of LFSR (around one third, i.e., 14 bits); we can obtain all the secret key bits. This cryptanalyzes Sprout with 2 attempts (considering constant time complexity required by the SAT solver in each attempt, which is around 1 minute in a laptop). This is less than the exhaustive key search. Further, we show how related ideas can be employed to mount a fault attack against Sprout that requires around 120 faults in random locations (20 faults, if the locations are known), whereas the designers claim that such a fault attack may not be possible. Our cryptanalytic results raise quite a few questions about this design paradigm in general that should be revisited with greater care.

A new lightweight cryptographic algorithm for enhancing data security in cloud computing

Abstract: Data has been pivotal to all facets of human life in the last decades. In recent years, the massive growth of data as a result of the development of various applications. This data needs to be secured and stored in secure sites. Cloud computing is the technology can be used to store those massive amounts of data. . The rapid development of this technology makes it more critical. Therefore, it has become urgent to secure data from attackers to preserve its integrity, confidentiality, protection, privacy and procedures required for handling it. This paper proposed a New Lightweight Cryptographic Algorithm for Enhancing Data Security that can be used to secure applications on cloud computing. The algorithm is a 16 bytes (128-bit) block cipher and wants 16 bytes (128-bit) key to encrypt the data. It is inspired by feistal and substitution permutation architectural methods to improve the complexity of the encryption. The algorithm achieves Shannon's theory of diffusion and confusion by the involvement of logical operations, such as (XOR, XNOR, shifting, swapping). It also features flexibility in the length of the secret key and the number of turns. The experimental results of the proposed algorithm presented a strong security level and an apparent enhancement in measures of cipher execution time and security forces compared to the cryptographic systems widely used in cloud computing.

A Highly Efficient Cipher Processor for Dual-Field Elliptic Curve Cryptography

Abstract: This brief presents a high-throughput dual-field elliptic-curve-cryptography (ECC) processor that features all ECC functions with the programmable field and curve parameters over both the prime and binary fields. The proposed architecture is parallel and scalable. Using 0.13-mum CMOS technology, the core size of the processor is 1.44 mm2 . The measured results show that our ECC processor can perform one 160-bit point scalar multiplication with coordinate conversion over the prime field in 608 mus at 121 MHz with only 70.0 mW and the binary field in 372 mus at 146 MHz with 82.1 mW. The ECC processor chip outperforms other ECC hardware designs in terms of functionality, scalability, performance, cost effectiveness, and power consumption. In addition, the system analysis shows that our design is very efficient, compared with the software implementation for realistic security applications.