An Improvement on the BGH Cryptosystem

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.

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.

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.

The article presents the EPES8–2 network with two round functions using the same algorithm for encryption and decryption. INTRODUCTION: Currently, block encryption algorithms based on the Feystel network are widely used. Block encryption algorithms based on the Feystel network include encryption algorithms such as DES, GOST 28147-89, as well as block encryption algorithms such as CAST 256, DFC, E2, LOKI97, which participated in the competition announced by NIST. The advantage of this network is that a single algorithm is used for encryption and decryption, only the encryption round keys are used in reverse order for decryption.

The majority of imaging techniques use symmetric and asymmetric cryptography algorithms to encrypt digital media. Most of the research works contributed in the literature focus primarily on the Advanced Encryption Standard (AES) algorithm for encryption and decryption. This paper propose an analysis for performing image encryption and decryption by hybridization of Elliptic Curve Cryptography (ECC) with Hill Cipher (HC), ECC with Advanced Encryption Standard (AES) and ElGamal with Double Playfair Cipher (DPC). This analysis is based on the following parameters: (i) Encryption and decryption time, (ii) entropy of encrypted image, (iii) loss in intensity of the decrypted image, (iv) Peak Signal to Noise Ratio (PSNR), (v) Number of Pixels Change Rate (NPCR), and (vi) Unified Average Changing Intensity (UACI). The hybrid process involves the speed and ease of implementation from symmetric algorithms, as well as improved security from asymmetric algorithms. ECC and ElGamal cryptosystems provide asymmetric key cryptography, while HC, AES, and DPC are symmetric key algorithms. ECC with AES are perfect for remote or private communications with smaller image sizes based on the amount of time needed for encryption and decryption. The metric measurement with test cases finds that ECC and HC have a good overall solution for image encryption.

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.

Lossless image compression and encryption using SCAN

Cryptography defines different methods and technologies used in ensuring that communication between two parties over any communication medium is secure, especially in presence of a third part. This is achieved through the use of several methods, such as encryption, decryption, signing, generating of pseudo-random numbers, among many others. Cryptography uses a key or some sort of a password to either encrypt or decrypt a message that needs to be kept secret. This is made possible using two classes of key-based encryption and decryption algorithms, namely symmetric and asymmetric algorithms. The best known and the most widely used public key system is ElGamal. This algorithm comprises of three phases, which are the key generation phase, encryption phase, and the decryption phase. Owing to the advancement in computing technology, ElGamal is prone to some security risks, which makes it less secure. The following paper previews combination of three paring function used to enhance the ElGamal algorithm and increase its security. The results showed that the modified algorithm gives 93% accuracy.KeywordsCryptographyElGamal algorithmEncryptionDecryptionCryptosystemSecurityPublic keyPrivate keyParing functions

In the rapid development of intelligent network connected vehicle, many information security risks have been exposed. The application of CAN bus encryption and decryption technology can solve the problem of safety communication in vehicle intranet. The sender and the receiver use the same set of key. The sender encrypts the data before sending it, and the receiver decrypts the data before applying it. In order to study the influence of CAN bus encryption and decryption on transmission efficiency, taking tc299, s32k144, mpc5606b and spc560b54 chips as examples, different encryption and decryption algorithms are used to encrypt and decrypt data of different lengths. The research shows that the time of symmetric encryption is much less than that of asymmetric encryption; With the increase of the length of the data to be encrypted and decrypted, the time required for encryption and decryption also increases; There is no significant difference in encryption and decryption efficiency between different chips. The time consumed by encryption and decryption is us level, which will not affect the real-time performance of the bus.

The Non-Reconciled Keys-based One-Time Pad (NRK-OTP) secure transmission scheme has attracted widespread attention since it reduces communication cost and computational complexity caused by information reconciliation. However, this scheme utilizes quantization to convert the analog channel estimates into binary sequences, which results in channel estimation errors being amplified. To address the problem, this letter proposes a Non-Quantization Keys-based One-Time Pad (NQK-OTP) secure transmission scheme. First, the uniformly distributed keys are generated from the wireless channel without quantization. Novel encryption and decryption algorithms are then presented to encrypt and decrypt modulated signals via OTP. Analytical and simulation results demonstrate that the proposed scheme can realize perfect secrecy and defend against symbol detection attacks. Compared with the NRK-OTP secure transmission scheme, the proposed scheme can achieve significant performance improvement in terms of Bit Error Rate (BER).

In delegated computation research, the main problem asks how a computationally weaker client device can obtain help from one or more computationally stronger servers to perform some computation. Desirable solution requirements include correctness of the computation, privacy of the inputs, high probability detection of any malicious behavior of a server, low client online runtime, low communication complexity, low client storage complexity, and minimal server trust. In this paper we investigate the problem of single-server delegated computation of the encryption and decryption algorithms in the ubiquitously applied RSA public-key cryptosystem. Our contribution includes state-of-the-art summaries, the first delegated computation protocol for small-exponent RSA encryption, a delegated computation protocol for RSA decryption with improved server runtime and client storage, and an upper bound on the impact of communication on client device energy, which may be of independent interest.

The wide spread of using handheld devices offers an opportunity for mobile devices to be used as a universal payment method. However, some issues impede the widespread acceptance of mobile payment; for example: privacy protection, limited capability of mobile devices, and limited bandwidth of wireless networks. In ecommerce payment, Secure Socket Layer (SSL) protocol has been used to establish a secure channel between customers and merchants to secure the payment and the order information. SSL has some disadvantages regarding customer privacy that the customer payment information is revealed to the merchant. Secure Electronic Transaction (SET) has resolved SSL protocol disadvantages by dividing order message into: 1) order information which is revealed to merchant M, 2) payment information which is revealed to Payment Gateway (PG). Both SSL and SET assume the existence of Public Key Infrastructure (PKI) where extensive computations are carried out. In mobile payment, the same protocols of ecommerce payment are used but their application is limited due to heavy computations over wireless and GSM networks. A Modified Secure Electronic Transaction (MSET) protocol is proposed to minimize the extensive computations of SET protocol through replacing time consuming public key encryption and decryption algorithms by symmetric key cryptography.

In Identity-Based Encryption (IBE) system, the Private Key Generator (PKG) holds the master secret key and is responsible for generating private keys for the users. This incurs the key-escrow problem, i.e. the PKG can decrypt any user' any ciphertexts without any possible detection. Also, compromising the master secret key will enable an adversary to do anything to the whole system, and having the master secret key be unavailable implies that new users cannot obtain private keys from the PKG, and existing users cannot get their private keys back from the PKG when they lost them. To address the key-escrow problem and protect the master secret key as much as possible with strong security and availability, distributed PKG protocols supporting threshold policy have been adopted in some IBE schemes. In this paper, we propose a distributed PKG protocol that supports the policy to be any monotonic access structures. Also, we propose the first distributed PKG protocol that supports the dynamic changes of the PKGs and the policy, while remaining the master secret key unchanged. The two protocols do not need any third party acting as a trusted dealer to present, and the master secret key should never be generated or resided in any one single site. The protocols are applicable to a generic IBE template, which covers many existing important IBE schemes. When applied to this generic type of IBE schemes, the two distributed PKG protocols do not affect the encryption and decryption algorithms, and only each user knows his own private key.