Eugeniusz Kuriata

Creation of Unequal Error Protection Codes for Two Groups of Symbols

Creation of Unequal Error Protection Codes for Two Groups of Symbols This article presents problems of unequal information importance. The paper discusses constructive methods of code generation, and a constructive method of generating asymptotic UEP codes is built. An analog model of Hammings upper bound and Hilberts lower bound for asymptotic UEP codes is determined.

Analysis of non-linear pseudo-noise sequences

In this paper method of generating keys for a stream-cipher on the base of non-linear pseudo-noise sequences is presented. The most important task, ensuring suitable security of the cryptographic system, is an appropriate key selection. There exist many key generation systems but they usually posses properties, which do not allow to design a safe system. In the paper, a method of performance analysis of sequences for cryptographic application is shown. To verification of this methods of keys generation is applied by statistical tests DIEHARD and linearity test, proposed by NIST.

Problems of Sending Sensitive Information

This paper addresses the problem of an electronic document generation in the case when sensitive information is proceded. Proposed schemes based on two-phase procedure of the message ciphering. It guarantees the required security level. In addition, all attributes of the physical carrier are satisfied. Furthermore, schemes are presented to illustrate clearly the proposed methodology of generating and deciphering the electronic document containing sensitive information.

Hash Chaining for Authenticated Data Structures Freshness Checking

In systems based on public key infrastructure in most cases we depend on trusted third party. Development of computer security systems and increase in popularity of public key infrastructure and its uses led to development of new data distribution methods — distribution based on untrusted publishers. It is possible to publish data by an untrusted publisher, however this data must contain authentication information in it. Validation of that information allows verification of information origin. Starting with certificate revocation list, certificate revocation trees we analyze these structures and find their strengths and weaknesses. By improving their strengths and eliminating their weaknesses we introduce a method for publishing data and their authentication information by an untrusted publisher. Basic concept of existing solutions is described in chapter 1. Chapter 2 introduced our method for publishing self authenticated data structures. Conclusions are described in chapter 3.

Accessibility of information in realtime systems

In the paper the problem of informations security defined as fulfilment of confidentiality, authenticity and accessibility is presented. The accessibility, as the element of security is especially importand in realtime systems, in which the time of replying to received information is limited, while undelivering the messages right on time is unacceptable. The accessibility of information is fulfiled thought application of error control coding, in particular by using cyclic Reed-Solomon codes.