Showing papers on "Cryptography published in 1975"

Some cryptographic techniques for machine-to-machine data communications

Abstract: Some of the threats to the integrity of multiuser teleprocessing systems and to the data they contain can be countered by the use of cryptography. Stream-generator ciphers are not ideally suited for such an application, thus the use of block ciphers, which have the beneficial property of a strong nonlinear intersymbol dependence, is suggested. This property provides the means for automatic error detection for verifying the authenticity of terminal operators, and for ensuring messase integrity. An experimental demonstration system has been constructed to illustrate protection features that can be provided for real applications.

Generators for Certain Alternating Groups with Applications to Cryptography

Abstract: A set of block ciphers is described which can readily be adapted for computer encipherment of data. The subgroup of permutations generated by any one of these ciphers is shown to be the alternating group, in all cases of interest, suggesting that such systems have a high level of security.

Key controlled block cipher cryptographic system

Abstract: A cryptographic system for encrypting a block of binary data under the control of a key consisting of a set of binary symbols. The cryptographic system may be utilized within a data processing environment to ensure complete privacy of data and information that is stored or processed within a computing system. All authorized subscribers who are permitted access to data within the network are assigned a unique key consisting of a combination of binary symbols. The central processing unit within the computing network contains a complete listing of all distributed authorized subscriber keys. All communications transmitted from terminal input are encrypted into a block cipher by use of the cryptographic system operating under the control of the subscriber key which is inputed to the terminal device. At the receiving station or central processing unit, an identical subscriber key which is obtained from internal tables stored within the computing system is used to decipher all received ciphered communications.

Generation of key in cryptographic system for secure communications

Abstract: Report discusses key generation for transmission of confidential data. A number of feedback functions are discussed for generation of long key sequences.