On Single-Server Delegation of RSA

Cryptographic technique is one of the principal means to protect information security. Not only has it to ensure the information confidential, but also provides digital signature, authentication, secret sub-storage, system security and other functions. Therefore, the encryption and decryption solution can ensure the confidentiality of the information, as well as the integrity of information and certainty, to prevent information from tampering, forgery and counterfeiting. Encryption and decryption algorithm's security depends on the algorithm while the internal structure of the rigor of mathematics, it also depends on the key confidentiality. Key in the encryption algorithm has a pivotal position, once the key was leaked, it means that anyone can be in the encryption system to encrypt and decrypt information, it means the encryption algorithm is useless. Therefore, what kind of data you choose to be a key, how to distribute the private key, and how to save both data transmission keys are very important issues in the encryption and decryption algorithm. This paper proposed an implementation of a complete and practical RSA encrypt/decrypt solution based on the study of RSA public key algorithm. In addition, the encrypt procedure and code implementation is provided in details.

Cloud is an evolving computing technology in which the services are provisioned dynamically through internet. The users’ data are stored in the remotely located servers that are maintained by cloud providers. The major security challenge in cloud is that the users cannot have direct control over the remotely stored data. To preserve the privacy of user’s data stored in the cloud, an efficient algorithm maintaining the confidentiality of data is proposed. We ensure that the data stored in the untrusted cloud server is confidential by developing a new data encryption algorithm. Unlike other encryption algorithms, our encryption algorithm needs lesser computation overhead. Encryption and decryption algorithms are developed in java and Remote Method Invocation (RMI) concepts are used for communication between client and server. Simulation environment is set up with the eucalyptus tool. This technique provides the data confidentiality with minimum computational overhead of the client.

The work presented in this paper targets on the Division operation i.e. division. Basic operations like addition, subtraction and multiplication are implemented using Vedic mathematics for various dedicated applications such as RSA encryption and decryption algorithm. The proposed work focuses on division operation which is an important operation in areas such as image processing, networking, signal processing, computer graphics, numerical application, scientific applications and in processor implementation. From the architectural point of view, hardware required by division circuits are usually much larger than the multiplier circuits for same data word length and division operation is generally categories as slow division and fast division. Where slow division is restoring and non-restoring methods and fast division is Newton Raphson and Goldschmidt methods. The Vedic division method is mathematically modeled and tested for feasibility and is compared with earlier implementation like restoring and non-restoring methods. The work carried out on division operation based on Vedic mathematics is limited to one of the Vedic sutra. In this paper the four Sutras are considered for implementation.

A novel quantum gray-level image encryption and decryption algorithm based on image correlation decomposition is proposed. The correlation among image pixels is established by utilizing the superposition and measurement principle of quantum states. And a whole quantum image is divided into a series of sub-images. These sub-images are stored into a complete binary tree array constructed previously and then randomly performed by one of the operations of quantum random-phase gate, quantum revolving gate and Hadamard transform. The encrypted image can be obtained by superimposing the resulting sub-images with the superposition principle of quantum states. For the encryption algorithm, the keys are the parameters of random phase gate, rotation angle, binary sequence and orthonormal basis states. The security and the computational complexity of the proposed algorithm are analyzed. The proposed encryption algorithm can resist brute force attack due to its very large key space and has lower computational complexity than its classical counterparts.

Based on blockchain technology, the Bitcoin and other cryptographic currencies have drawn great public attention recently. In addition to the soaring in finance sector, this technology has been emerged into various application scenarios from transportation, healthcare, entertainment, Internet of Things (IoT), etc. However, most popular blockchain systems with proof-of-work (PoW) as their consensus mechanism are faced with an extremely high latency, i.e. only tens of transactions can be accomplished in one second and it takes up to hours to confirm a transaction. Byzantine fault tolerance (BFT) enables a small network to reach consensus rapidly, yet the high inter-node communications degrade its scalability. To break the bottleneck of the communication complexity, we consider Practical Byzantine Fault Tolerance (PBFT) protocol and discuss a double-layer PBFT-based consensus mechanism in this chapter. The proposed mechanism re-distributes nodes into two layers in groups, where the members of the first layer act as the leader of each group in the second layer. We theoretically demonstrate that this double-layer PBFT significantly reduces the system communication complexity. It is also proved that the complexity is optimal when the nodes are evenly distributed in each group in the second layer. The security threshold is analyzed based on the faulty probability-determined (FPD) and the faulty number-determined (FND) models, respectively. Besides, a practical protocol for the proposed double-layer PBFT system is proposed.

Cybertwin-driven-based network architecture for sixth generation (6G) is a new cloud-centric network architecture, which was put forward to address challenges of 6G, such as scalability, security, mobility, and availability. As more and more users’ data are obtained and converted into other digital asset by the cybertwin, relevant techniques of data management to enhance privacy and security becomes a key challenge for Cybertwin-driven 6G. The double authentication preventing ring signature (DAPRS) is a cryptographic primitive that meets requirements of authenticity, anonymity of users’ private data, and linkability of users’ misbehavior, so it is suitable for monitoring behaviors of risky users. In this article, we propose a post-quantum secure ring signature to enhance security and privacy in Cybertwin-driven 6G (PRSG). In the PRSG, we first put forward an accumulator based on a chameleon hash function that allows to efficiently prove knowledge of an accumulated value. Then, we construct a DAPRS based on the accumulator and the zero-knowledge argument of knowledge. Finally, we present how to use the DAPRS to build a secure and efficient privacy-preserving scheme in the Cybertwin-driven 6G. Security proof shows that this scheme achieves anonymity, unforgeability, as well as double signature extractability. Also, we make some security analysis and performance evaluation to demonstrate that the PRSG has low communication complexity, high performance, and privacy preservation in the cybertwin-driven 6G.

Based on a particular overlapping domain decomposition technique, a parallel finite element discretization algorithm for the generalized Stokes equations is proposed and investigated. In this algorithm, each processor computes a local approximate solution in its own subdomain by solving a global problem on a mesh that is fine around its own subdomain and coarse elsewhere, and hence avoids communication with other processors in the process of computations. This algorithm has low communication complexity. It only requires the application of an existing sequential solver on the global meshes associated with each subdomain, and hence can reuse existing sequential software. Numerical results are given to demonstrate the effectiveness of the parallel algorithm.

Natural distributed systems are adaptive, scalable and fault-tolerant. Emergence science describes how higher-level self-regulatory behaviour arises in natural systems from many participants following simple rule-sets. Emergence advocates simple communication models, autonomy and independence, enhancing robustness and self-stabilization. High-quality distributed applications such as autonomic systems must satisfy the appropriate nonfunctional requirements which include scalability, efficiency, robustness, low-latency and stability. However the traditional design of distributed applications, especially in terms of the communication strategies employed, can introduce compromises between these characteristics. This paper discusses ways in which emergence science can be applied to distributed computing, avoiding some of the compromises associated with traditionally-designed applications. To demonstrate the effectiveness of this paradigm, an emergent election algorithm is described and its performance evaluated. The design incorporates nondeterministic behaviour. The resulting algorithm has very low communication complexity, and is simultaneously very stable, scalable and robust.

Performance of a relay-assisted hybrid FSO/RF communication system

In recent years, the security of multimedia data transmitted over insecure networks like the Internet has gained a lot of attention. Applying standard cryptographic encryption and authentication algorithms to multimedia data is not feasible because multimedia data may undergo certain content preserving operations that although may change the data values but keep the semantic of the data intact. In this paper, we propose a robust encryption algorithm for digital images that not only provides confidentiality to the image being transmitted or stored, but it can also tolerate JPEG compression. The proposed algorithm is private key i.e. the encryption and decryption process requires the same key. This paper presents an interesting approach by adapting techniques from modern control theory to devise the proposed encryption and decryption algorithms. The results reported in this paper are extremely encouraging and reflects the point that how multi-disciplinary fields can be combined to solve complex problems.

In order to solve the problem of lighting waste in developing countries and backward areas, an application of Internet of Things technology, combined with edge computing, is proposed to achieve intelligent lighting system for office buildings. The system takes the Internet of Things technology as the core, and combine ZigBee short‐distance, low complexity, low‐rate, low‐power, low‐cost and two‐way wireless communication advantage, and based on mesh topology designs an energy‐saving system for office building lighting. Intelligently control the switch of the luminaire or switch the preset illumination mode according to the sensed number of people in the current office, location and illumination brightness, effectively overcomes the defects of traditional lighting mode management backwardness, waste of energy, poor comfort and complicated wiring. The objective is to achieve the goal of energy saving and consumption reduction for office building lighting. Through practice and experimental test analysis, the improved energy consumption of the energy saving is about 30% per year, and the effect is remarkable.

Interference alignment (IA) is a promising technique for interference mitigation in multicell networks due to its ability to completely cancel the intercell interference through linear precoding and receive filtering. In small networks, the amount of required channel state information (CSI) is modest and IA is, therefore, typically applied jointly over all base stations. In large networks, where the channel coherence time is short in comparison to the time needed to obtain the required CSI, base station clustering must be applied however. We model such clustered multicell networks as a set of coalitions, where CSI acquisition and IA precoding are performed independently within each coalition. We develop a long-term throughput model, which includes both CSI acquisition overhead and the level of interference mitigation ability as a function of the coalition structure. Given the throughput model, we formulate a coalitional game where the involved base stations are the rational players. Allowing for individual deviations by the players, we formulate a distributed coalition formation algorithm with low complexity and low communication overhead that leads to an individually stable coalition structure. The dynamic clustering is performed using only long-term CSI, but we also provide a robust short-term precoding algorithm, which accounts for the intercoalition interference when spectrum sharing is applied between coalitions. Numerical simulations show that the distributed coalition formation is generally able to reach long-term sum throughputs within 10% of the global optimum.

Cryptography is the science that uses the calculation and math behind the procedures to encrypt and decrypt data. The process that is used to convert the message (text, picture, sound, and video) into cipher message is known as encryption. The encryption algorithm is used to encrypt a message at the transmitter, while the decryption algorithm is applied to decrypt the received encrypted message. In a cryptosystem, the synchronization of the transmitter and receiver sides has to be secured. One can use a key during encryption and decryption process.

Cryptography is the science of using mathematics to encrypt and decrypt data.It enables to store sensitive information or transmit it across insecure networks so that it cannot be read by anyone except the intended recipient.While cryptography is the science of securing data, cryptanalysis is the science of analyzing and breaking secure communication.A common goal of cryptographic research is to design protocols that provide a confidential and authenticated transmission channel for messages over an insecure network.A cryptographic algorithm is considered to be computationally secured if it cannot be broken with standard resources, either current or future and apart from the algorithm distribution of keys also more important is to make an efficient cryptosystem.TACIT Encryption Algorithm can produce best possible results if key size is the size of the packet expected to pass through the network is small.This paper gives the comparison of the various algorithms with TACIT Encryption Algorithm on the basis of parameters like key length, block size, type and features.The paper is based on the chip designing of the algorithm using VHDL programming language.

This paper proposes a ternary subset difference method (SD method) that is resistant to coalition attacks. In order to realize a secure ternary SD method, we design a new cover-finding algorithm, label assignment algorithm and encryption algorithm. These algorithms are required to revoke one or two subtrees simultaneously while maintaining resistance against coalition attacks. We realize this two-way revocation mechanism by creatively using labels and hashed labels. Then, we evaluate the efficiency and security of the ternary SD method. We show that the number of labels on each client device can be reduced by about 20.4 percent. The simulation results show that the proposed scheme reduces the average header length by up to 15.0 percent in case where the total number of devices is 65, 536. On the other hand, the computational cost imposed on a client device stays within O(log n). Finally, we prove that the ternary SD method is secure against coalition attacks.