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.

Apparatuses for encoding, decoding, and authenticating data in cipher block chaining messaging authentication code

Abstract: A processor is provided that includes inputs to receive headers and payloads of messages in block form, a cipher key, a counter block, and an indication that a data block is ready to be received at the processor's first input, and that outputs a data block processes according to a CCM protocol and a signal requesting the provision of a data block at the processor input. The processor also includes first and second cipher circuits generating ciphered results that are a function of a input data block and an input cipher key. Furthermore, the processor includes a controller that processes a first sequence of data blocks through the first cipher circuit to generate a message integrity code and a second sequence of data blocks through the second cipher circuit to generate a set of ciphered data blocks.

Method and system for signing JavaScript object notation (JSON) messages

Abstract: The confidentiality of JavaScript Object Notation (JSON) message data is secured using an encryption scheme. The encryption scheme implements a JSON encryption syntax, together with a set of processing rules for creating encrypting arbitrary data in JSON messages in a platform/language independent manner. A method for encrypting a data item in a JSON message begins by applying an encryption method and a key to the data item to generate a cipher value. A data object is then constructed that represents an encryption of the data item. The data item in the JSON message is then replaced with the data object, and the resulting modified JSON message is then output from a sending entity. At a receiving entity, information in the data object is used to re-generate the data item, which is then placed back in the original message.

Improvement of the Security of ZigBee by a New Chaotic Algorithm

Abstract: The security protocols used in ZigBee rely on an advanced encryption standard-counter mode (AES-CTR) algorithm to encrypt data before transmission. This algorithm is very robust, but it is time consuming. For some industrial and medical applications, it does not meet the real-time requirement. When the AES is used in counter mode CTR, it becomes like a stream cipher that aims to generate pseudorandom bits. Also, to encrypt data, the latter are combined with the plaintext using the XOR operation. New fast stream ciphers were proposed for the eStream project, but these ciphers have shown some weakness. On the other hand, ciphers based on chaotic functions seem to be more promising. Detailed analyses have shown that chaotic functions have very good cryptographic properties and can be used to construct high speed and strong stream ciphers. In this paper, a new robust and fast chaotic encryption algorithm RFCA is presented. This consists of a chaotic cipher composed of two perturbed maps piecewise linear chaotic map. This algorithm is, in particular, adequate for data encryption in ZigBee networks where robustness and real time are both essential. A comparison between our algorithm (RFCA) and the AES-CTR, the simplified AES, and the eStream finalist candidates, is presented with regard to speed and robustness. This is done using correlation coefficients, unified average changing intensity, number of pixels change rate, and test of randomness for the generated bit sequences using the National Institute of Standards and Technology statistical test suite.

Medical Image Encryption and Compression Scheme Using Compressive Sensing and Pixel Swapping Based Permutation Approach

Abstract: This paper presents a solution to satisfy the increasing requirements for secure medical image transmission and storage over public networks. The proposed scheme can simultaneously encrypt and compress the medical image using compressive sensing (CS) and pixel swapping based permutation approach. In the CS phase, the plain image is compressed and encrypted by chaos-based Bernoulli measurement matrix, which is generated under the control of the introduced Chebyshev map. The quantized measurements are then encrypted by permutation-diffusion type chaotic cipher for the second level protection. Simulations and extensive security analyses have been performed. The results demonstrate that at a large scale of compression ratio the proposed cryptosystem can provide satisfactory security level and reconstruction quality.

A Differential Fault Analysis on AES Key Schedule Using Single Fault

Abstract: Literature on Differential Fault Analysis (DFA) on AES-128 shows that it is more difficult to attack AES when the fault is induced in the key schedule, than when it is injected in the intermediate states. Recent research shows that DFA on AES key schedule still requires two faulty cipher texts, while it requires only one faulty cipher text and a brute-force search of $2^8$ AES-128 keys when the fault is injected inside the round of AES. The present paper proposes a DFA on AES-128 key schedule which requires only one single byte fault and a brute-force search of $2^8$ keys, showing that a DFA on AES key schedule is equally dangerous as a fault analysis when the fault is injected in the intermediate state of AES. Further, the fault model of the present attack is a single byte fault. This is more realistic than the existing fault model of injecting three byte faults in a column of the AES key which has a less chance of success. To the best of our knowledge the proposed attack is the best known DFA on AES key schedule and requires minimum number of faulty cipher text. The simulated attack, running on 3GHz Intel Core 2 Duo desktop machine with 2GB RAM, takes around 35 minutes to reveal the secret key.