Unique Information and Secret Key Decompositions

The unique information ($UI$) is an information measure that quantifies a deviation from the Blackwell order. We have recently shown that this quantity is an upper bound on the one-way secret key rate. In this paper, we prove a triangle inequality for the $UI$, which implies that the $UI$ is never greater than one of the best known upper bounds on the two-way secret key rate. We conjecture that the $UI$ lower bounds the two-way rate and discuss implications of the conjecture.Comment: 7 page

Імовірнісний алгебраїчний криптоаналіз шифратора «SFINKS» з певним класом фільтруючих функцій

Експериментально знайдено ключ потокового шифратора «SFINKS» з послабленою фільтруючою функцією за допомогою імовірнісної алгебраїчної атаки. Клас таких вразливих функцій досить широкий і містить багато функцій, стійких проти відомих неалгебраїчних методів криптоаналізу.Stream cipher «SFINKS» with weakened filtering function is considered. Practical cryptanalysis was done by means of probabilistic algebraic attack. There are a number of such vulnerable functions and some of them are resistant against known non-algebraic methods of cryptanalysis

Код умовних лишків і цілісність інформаційних об’єктів

Досліджені можливості застосування в задачах забезпечення цілісності інформаційних об’єктів в телекомунікаційних мережах узагальненого завадостійкого коду умовних лишків та здійснено аналіз його можливостей.Explored possibilities of application in telecommunication networks in the tasks of providing of integrity of information’s holding object of the generalized ant jamming code of conditional tailings. Description of such code is offered and carried out the analysis of his possibilities

Secure Dynamic Groups Auditing Service with Group Signature for Cloud Storage

Cloud storage has become a commonplace of storing and sharing data across multiple users. It is a challenge to preserve confidentiality and maintain identity privacy while sharing data within multiple dynamic groups, due to frequent change in the membership. Also, maintaining data integrity is an issue as data is stored and audited by untrusted cloud service provider (CSP). In this paper, we propose, third party auditor (TPA) auditing scheme to maintain data integrity and enabling TPA to perform audits for multiple users efficiently and simultaneously. By exploiting group signature scheme any member can anonymously share data within the group. The efficiency and the computation cost of the proposed system are independent with the number of users revoked and the data stored on the cloud. DOI: 10.17762/ijritcc2321-8169.150612

Algebraic Attacks on the Crypto-1 Stream Cipher in MiFare Classic and Oyster Cards

MiFare Crypto 1 is a lightweight stream cipher used in London\u27s Oyster card, Netherland\u27s OV-Chipcard, US Boston\u27s CharlieCard, and in numerous wireless access control and ticketing systems worldwide. Recently, researchers have been able to recover this algorithm by reverse engineering. We have examined MiFare from the point of view of the so called algebraic attacks . We can recover the full 48-bit key of MiFare algorithm in 200 seconds on a PC, given 1 known IV (from one single encryption). The security of this cipher is therefore close to zero. This is particularly shocking, given the fact that, according to the Dutch press, 1 billion of MiFare Classic chips are used worldwide, including in many governmental security systems

Алгоритм розподілу ресурсів інформаційної безпеки документальних телекомунікацій

Аналізується задача оптимізації витрат на інформаційну безпеку системи документальних телекомунікацій, яка зводиться до задачі багатокритеріального вибору. Пропонується інтерактивна процедура раціонального вибору варіанту розподілу витрат.The expenses optimization task of information security of the documental telecommunication systems is analyzed. Whole thing comes to multi criteria choice task. The interactive procedure of rational choice of the expenses distribution variant is offered

A nonlinear invariant attack on T-310 with the original Boolean function

There are numerous results on nonlinear invariant attacks on T-310. In all such attacks found so far, both the Boolean functions and the cipher wiring were contrived and chosen by the attacker. In this article, we show how to construct an invariant attack with the original Boolean function that was used to encrypt government communications in the 1980s

Методика оценки эфективности поточных шифров

Наводиться удосконалена система критеріїв і показників ефективності функціонування схем потокового шифрування, яка дозволяє відібрати допустимі параметри шифру таким чином, щоб відповідати вимогам криптографічної стійкості, оптимальності та адаптивності. На основі цієї системи пропонується методика дослідження ефективності потокових шифрів, призначена безпосередньо для оцінювання нових та відомих шифрів і проведення їх порівняльного аналізу.In this paper the improved system of criteria and metrics of operation efficiency of the stream encryption schemes, that allow to select valid parameters of the cipher so that to satisfy the requirement of cryptographic security, optimality and adaptivity is proposed. On the basis of this system the technique of research of efficiency of the stream ciphers intended directly for estimation of the new and known ciphers and for making the comparative analysis of their is offered

Unique Informations and Deficiencies

Given two channels that convey information about the same random variable, we introduce two measures of the unique information of one channel with respect to the other. The two quantities are based on the notion of generalized weighted Le Cam deficiencies and differ on whether one channel can approximate the other by a randomization at either its input or output. We relate the proposed quantities to an existing measure of unique information which we call the minimum-synergy unique information. We give an operational interpretation of the latter in terms of an upper bound on the one-way secret key rate and discuss the role of the unique informations in the context of nonnegative mutual information decompositions into unique, redundant and synergistic components.Comment: 13 pages, 2 figures. The material in this manuscript was presented at the 56th Annual Allerton Conference on Communication, Control, and Computing, 2018. This manuscript contains some corrections: most notably, Lemma 18 was removed and Proposition 28 was corrected. The numbering of equations and results in this version agrees with the numbering of the published versio