本文给出了特征为3 的域上的椭圆曲线点的计算方法，提出了3P 的计算思想；并将特征为2的域上的椭圆曲线点的一些特殊的快速计算方法移植到特征为3 的域上，同时对这几种方法进行了比较；由此给出域F3n上的椭圆曲线射影坐标的一种很好的表示法。

In this paper we introduce a new approach of constructing time capsule signature. Our new construction captures the basic requirements defined by dodis et al., and it is also very straightforward andflexible. The time capsule signature provides an elegant way to produce a "future signature" that becomesvalid from a specific future time t, when a trusted third party (called Time Server) publishes sometrapdoor information associated with the time t. It also has many other advantages. Our work includesa developed security model of time capsule signature, a novel way of construction based on the bipartitering signature, which is proven secure in the random oracle model and a concrete realization of thescheme.

We study the lattice of linear relations with integral coef-ficients between the logarithms of algebraic numbers. We prove that thereexists a "little" free family in the lattice by an autonomous demonstrationusing the classical theorems of Minkowski.RESUME-Nous étudions le réseau constitué parl' ensemble des re-lations linéaires coefficients entiers liant des logarithmes de nombresalgébriques. Nous montrons qu'il existe une "petite" famine fibre dans ceréseau par une d6monstration autonome utilisant les théorémes classiquesde Minkowski.