可乘的

However, though my little Periagua was finish'd; yet the Size of it was not at all answerable to the Design which I had in View, when I made the first; I mean, Of venturing over to the Terra Firma, where it was above forty Miles broad; accordingly, the Smallness of my Boat assisted to put an End to that Design, and now I thought no more of it: But as I had a Boat, my next Design was to make a Tour round the Island; for as I had been on the other Side, in one Place, crossing as I have already describ'd it, over the Land; so the Discoveries I made in that little Journey, made me very eager to see other Parts of the Coast; and now I had a Boat, I thought of nothing but sailing round the Island.

我造的第一只独木舟是相当大的，因为我想用它渡到小岛对面的那块大陆上去，期间的距离约有四十海里。可是，现在新造的这艘船就太小了，不可能乘它渡过那么宽的海域，因而不符合我原先造船的意图。这样，我只好打消我原定的计划，不再去想它了。现在既然有了这只小舟，我的下一步计划就是坐上小船绕岛航行一圈。前面我曾提到，我曾经在陆上徒步横越小岛，抵达了岛的另一头。在那些小小的旅行中，我有不少新的发现，所以我一直想看看小岛沿岸的其他地区。现在，我既然有了小船，就可沿岛航行一周，实现我的宿愿了。

This paper first analyses and summarizes the ststus quo and evolution trend of encryption, some common used cryptograph are introduced, including the algorithms used in symmetric cryptosystem and asymmetirc cryptosystem. We describe the theory of each algorithms and compare the elliptic curve cryptosystem with the other two asymmetric cryptosystems to show the advantages of this algorithm. Second, the principle of ECC is discussed, including the math foundation of ECC, basic conception of elliptic curves, constructiong idea of ECC, operation on the elliptic curve and so on. Third, the current attacks of ECC were analyzed deeply, and an algorithm based on limited prime number field was constructed. We analyzed its realizability in theory, and implement it by using certain function of MIRACL software package. Latter half in this paper, the implementation model of a simple elliptic curve encryption system which based on GF has been introduced. The paper also put a deep analysis on the algorithm of point addition and point multiplication.

本文首先对密码技术的发展现状及其发展趋势进行了分析和综述，详细的介绍了私钥密码系统和公钥密码系统的发展，说明各种算法的原理和优缺点，并给出了一些典型的密码体制的简要分析，重点将椭圆曲线算法与其它几种公钥密码算法比较，说明椭圆曲线算法的优势；其次，探讨了椭圆曲线密码体制的原理，包括椭圆曲线密码的数学基础、基本概念、椭圆曲线密码体制的构造思想等问题；第三作者对椭圆曲线的攻击现状作了详细的分析，针对所使用的大素数域F_p，设计了素数域上安全椭圆曲线产生的算法，从理论上做了可实施性分析，从软件上做了具体实现；在本文的后半部分，提出了一个简单的基于有限素数域上的椭圆曲线加密方按算实现模型，并对SECES中设计的点加和点乘运算进行了深入分析。

Firstly a fast direct computing 3kP algorithm in field was deduced,which only needed one inversion;the new double base number chain based on 1/2 and 3 could be integrated with high-speed direct computing 3kP and halving algorithm.Scalar multiplication based on the new chain only employed point addition,halving algorithm,triplication and direct...

在底层域推导出直接计算3kP的快速算法，该算法只需一次求逆；新设计的以1/2和3为基的双基数编码可结合高效的直接计算3kP和折半运算，基于该双基数编码的标量乘算法只涉及到点加运算、折半运算、三倍点和直接计算3kP，底层域运算复杂性得到降低，在NIST推荐的椭圆曲线上比Dimitrov算法效率提高70%以上，比Wong方法提高10%以上。

The modular design of printNet system is divided into several application part, such as data processing tools, design tools, products, Business card printing tools, and solutions to technical tools, of which the highest is a design tool over the actions that it printLayout from page formatting and setting variables, but also can be used by an operator in a transform tool programming, so that the contents of the variables in a database in output for operations, now produetion of mostly to one-dimensional bar codes and encrypted bit or anti-false, the party is a method in the bar code by addition, subtraction, multiplication, Division, opinins Mo, and so after the results or the results of data, or the result is converted to the data that corresponds to a location in one of the ntehs detection accuracy is valid, just make a bit of the inverse operation, the operation that results in comparison with the original data, such as the same as the data is valid, such as different then the data is not valid, this scenario is the most simple and most primitive anti-counterfeit. PrintNet software to complex product environment " interpuntion and output the integration of integrated management " solution possible.

printNet系统的模块式设计分为几个应用部分，如数据处理工具、设计工具、产品制卡工具以及方案解决工具，其中技术含量最高的是对设计工具printLayout的操作，它除了设计页面格式和设置变量外，还可由操作员在转换工具中编程，以便对数据库中的变量内容在输出时进行运算操作，现在生产中应用的大多是给一维条码加校验位或是防伪加密，其方一法是将条码中的数据经过加、减、乘、除、取莫等运算后，将结果或将结果中的几位至于数据后，或将结果转换成对应符号放在数据中的某个位置，如须检测某一数据是否准确有效，只要把校验位上的数进行逆运算，把运算结果与原数据比较，如相同则数据有效，如不同则数据无效，这种方案是最简单最原始的防伪加密的方法。printNet软件系统使得在复杂产品环境下的&排版与输出一体管理&的集成解决方案成为可能。

SHOULD NEVERTHELESS ANY CARGO BE LOADED, BY VESSEL IN PLACES NOT ACCESSIBLE TO GRABS AND/OR BULLDOZERS OR OTHER EQUIPMENT ANY TIME AND/OR DISPATCH MONEY SO LOST AND ALL EXTRA EXPENSES OVER AND ABOVE THE COST OF NORMAL GRAB DISCHARGE AT PORT OF DISCHARGE TO BE FOR SELLERS ACCOUNT.

应该然而任何的货物被装载，乘坐船在地方中不是可接近到抓握及推土机或其他的仪器任何时候及在解除的港口派遣钱如此失去及在正常抓握解除的费用上面的在及上的所有额外的费用为卖方帐户。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。