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.

On the construction of block ciphers provably secure and not relying on any unproved hypotheses (extended abstract)

Abstract: One of the ultimate goals of cryptography researchers is to construct a (secrete-key) block cipher which has the following ideal properties: (1) The cipher is provably secure, (2) Security of the cipher does not depend on any unproved hypotheses, (3) The cipher can be easily implemented with current technology, and (4) All design criteria for the cipher are made public. It is currently unclear whether or not there really exists such an ideal block cipher. So to meet the requirements of practical applications, the best thing we can do is to construct a block cipher such that it approximates the ideal one as closely as possible. In this paper, we make a significant step in this direction. In particular, we construct several block ciphers each of which has the above mentioned properties (2), (3) and (4) as well as the following one: (1') Security of the cipher is supported by convincing evidence. Our construction builds upon profound mathematical bases for information security recently established in a series of excellent papers.

Cryptographic decoder for computer programs

Abstract: An integrated circuit decoder for providing microcomputer users with access to several proprietary programs selected from a large group of such programs that have been distributed to users in cipher. The decoder chip can decipher a program if an enciphered key called a "permit code" is presented to the decoder chip. Permit codes are not interchangeable between decoders, are issued only to customers that have paid for use of a program product, and each code will work only with one program. As the program is being deciphered in a user's microcomputer, the decoder chip places random errors into the program which make copies of the program malfunction in other microcomputers. The decoder chip keeps a table of addresses where it has placed errors and dynamically corrects the errors on the data bus whenever an error word is addressed during execution. Using such a decoder, thousands of individually priced proprietary software products can be delivered securely to prospective customers in advance of sales on laserdiscs, diskettes, TV-cables, and digital radio broadcasts.

Encryption system key distribution method and apparatus

Abstract: Encryption systems typically rely on the distribution of cipher keys between terminals for scrambling and unscrambling transmitted messages. Elaborate security precautions are necessary to protect the cipher keys since a compromise of the key could result in a compromise of the transmission. There is disclosed a key distribution method and apparatus which uses a channel (14, 15, 18) from identified terminals (A, B, X) to a central key distribution center (KDC) for the establishment, on a one-session basis, of the key which is to be used for the next session between those terminals. The key establishing link (16) is itself encoded using a cipher key which changes after each usage. Provision is made to verify, for each new connection, that a compromise has not priorly occurred.

A commutative digital image watermarking and encryption method in the tree structured Haar transform domain

Abstract: In this paper a commutative watermarking and ciphering scheme for digital images is presented. The commutative property of the proposed method allows to cipher a watermarked image without interfering with the embedded signal or to watermark an encrypted image still allowing a perfect deciphering. Both operations are performed on a parametric transform domain: the Tree Structured Haar transform. The key dependence of the adopted transform domain increases the security of the overall system. In fact, without the knowledge of the generating key it is not possible to extract any useful information from the ciphered-watermarked image. Experimental results show the effectiveness of the proposed scheme.

Secured Data Collection With Hardware-Based Ciphers for IoT-Based Healthcare

Abstract: There are tremendous security concerns with patient health monitoring sensors in Internet of Things (IoT). The concerns are also realized by recent sophisticated security and privacy attacks, including data breaching, data integrity, and data collusion. Conventional solutions often offer security to patients’ health monitoring data during the communication. However, they often fail to deal with complicated attacks at the time of data conversion into cipher and after the cipher transmission. In this paper, we first study privacy and security concerns with healthcare data acquisition and then transmission. Then, we propose a secure data collection scheme for IoT-based healthcare system named SecureData with the aim to tackle security concerns similar to the above. SecureData scheme is composed of four layers: 1) IoT network sensors/devices; 2) Fog layers; 3) cloud computing layer; and 4) healthcare provider layer. We mainly contribute to the first three layers. For the first two layers, SecureData includes two techniques: 1) light-weight field programmable gate array (FPGA) hardware-based cipher algorithm and 2) secret cipher share algorithm. We study KATAN algorithm and we implement and optimize it on the FPGA hardware platform, while we use the idea of secret cipher sharing technique to protect patients’ data privacy. At the cloud computing layer, we apply a distributed database technique that includes a number of cloud data servers to guarantee patients’ personal data privacy at the cloud computing layer. The performance of SecureData is validated through simulations with FPGA in terms of hardware frequency rate, energy cost, and computation time of all the algorithms and the results show that SecureData can be efficient when applying for protecting security risks in IoT-based healthcare.