In this paper, a new broadcast encryption scheme is presented based on threshold secret sharing and secure multiparty computation. This scheme is maintained to be dynamic in that a broadcaster can broadcast a message to any of the dynamic groups of users in the system and it is also fair in the sense that no cheater is able to gain an unfair advantage over other users. Another important feature...

2 The Riordan skew algebra K[[x]] ⋊ M of formal power series under multiplication and substitution 3 2.1 Basics on formal power series . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Skew algebra of formal power series under substitution . . . . . . . . . . 4 2.2.1 Right-distributive algebras . . . . . . . . . . . . . . . . . . . . . . 5 2.2.2 Substitution of formal power series . . . . ....

Let $K$ be a field of characteristic$p>0$, $K[[x]]$, the ring of formal power series over $ K$,$K((x))$, the quotient field of $ K[[x]]$, and $ K(x)$ the fieldof rational functions over $K$. We shall give somecharacterizations of an algebraic function $fin K((x))$ over $K$.Let $L$ be a field of characteristic zero. The power series $finL[[x]]$ is called differentially algebraic, if it satisfies...

the book titled “bases of politics” is the original text for students of bachelor of political sciences which is taught in a three-unit course. this compilation has been introduced as the best reference for bases of politics course and master of science exam. we first introduce this text and assert its assumptions and then evaluate and criticize in contain and formal manner and finally after pr...

This study on farmers’ perception and management of natural hazards in production and security of farm investment was carried out in Isuikwuato Local Government Area of Abia State, Nigeria. The study was sought to identify farmers’ perceived natural hazards in food production; identify adopted measures used in mitigating impacts of the hazards and determined factors that influenced farmers from...