assignmentutor™您的专属作业导师

assignmentutor-lab™ 为您的留学生涯保驾护航 在代写密码学Cryptography & Cryptanalysis方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写密码学Cryptography & Cryptanalysis代写方面经验极为丰富，各种代写密码学Cryptography & Cryptanalysis相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 数学代写|密码学作业代写Cryptography & Cryptanalysis代考|Hill Cipher

The Hill cipher was invented by Lester A. Hill in 1929. It is a bit more complex than other cipher we have studied thus far. It is based in linear algebra and uses matrix mathematics. We will be exploring those topics in much more detail in later chapters. To encrypt a message, you break the plaintext into a block of $n$ letters. Each letter being represented by a number $(\mathrm{a}=1, \mathrm{~b}=2, \mathrm{c}=3$, etc.) it should be noted that the number assignment is not critical. Some implementations start with a $=0$. That block of numbers representing the block of plaintext forms a matrix that is multiplied by some invertible $n \mathrm{X} n$ matrix, mod 26. If you do not have some math background, this may seem rather intimidating, not to worry, it will all be made clear.

The matrix used is the key for this cipher. It should be selected randomly and be mod 26 (26 for the alphabet used in English, other alphabets would require a different mod). For our discussions on this cipher, we will use the following matrix as a key:
$$\left[\begin{array}{ccc} 4 & 5 & 10 \ 3 & 8 & 19 \ 21 & 5 & 14 \end{array}\right]$$
Bear in mind that while I am showing you a $3 \times 3$ matrix, any size can be used as long as it is a square. For those readers not familiar with matrix math, I will show you just enough to allow you to understand the Hill cipher. Chapters 4 and 5 will give you a better introduction to mathematics for cryptography. To understand multiplying a matrix by a vector, examine this example using letters.

## 数学代写|密码学作业代写Cryptography & Cryptanalysis代考|The Vernam Cipher

The Vernam cipher is a type of one-time pad (Mollin 2000). The concept behind a one-time pad is that the plaintext is somehow altered by a random string of data so that the resulting ciphertext is truly random. Gilbert Vernam (April 3, 1890, to February 7, 1960) proposed a stream cipher that would be used with teleprinters. It would combine character by character a prepared key that was stored on a paper tape, with the characters of the plaintext to produce the ciphertext. The recipient would again apply the key to get back the plaintext.

In 1919, Vernam patented his idea (U.S. Patent 1,310,719). In Vernam’s method, he used the binary XOR (Exclusive OR) operation applied to the bits of the message. We will be examining binary operations including XOR, in more detail in Chap. $4 .$ To truly be a one-time pad, by modern standards, a cipher needs two properties. The first is suggested by the name: the key is only used once. After a message is enciphered with a particular key, that key is never used again. This makes the one-time pad quite secure, but also very impractical for ongoing communications such as one encounters in e-commerce. The second property is that the key be as long as the message. That prevents any patterns from emerging in the ciphertext. It should be noted that Vernam also patented three other cryptographic inventions: U.S. Patent 1,416,765; U.S. Patent 1,584,749; and U.S. Patent 1,613,686.

One-time pads are still used for communications today, but only for the most sensitive communications. The keys must be stored in a secure location, such as a safe, and used only once for very critical messages. The keys for modern one-time pads are simply strings of random numbers sufficiently large enough to account for whatever message might be sent.

## 数学代写|密码学作业代写Cryptography & Cryptanalysis代考|Hill Cipher

Hill 密码是 Lester A. Hill 在 1929 年发明的。它比我们迄今为止研究过的其他密码要复杂一些。它基于线性代数并使用矩阵数学。我们将在后面的章节中更详细地探讨 这些主题。要加密消息，您需要将明文分成一个块 $n$ 字母。每个字母由一个数字表示 $(\mathrm{a}=1, \mathrm{~b}=2, \mathrm{c}=3$ 等) 应注意，编号分配并不重要。一些实现以 $=0$ 代表明 文块的数字块形成一个矩阵，该矩阵乘以一些可逆 $n \mathrm{X} n$ matrix， mod 26. 如果你没有一些数学背景，这可能看起来相当吓人，不用担心，一切都会弄清楚的。

## 数学代写|密码学作业代写Cryptography & Cryptanalysis代考|The Vernam Cipher

Vernam 密码是一种一次性密码（Mollin 2000）。一次性密文背后的概念是，明文以某种方式被随机数据串改变，因此生成的密文是真正随机的。Gilbert Vernam（1890 年 4 月 3 日至 1960 年 2 月 7 日）提出了一种用于电传打印机的流密码。它将逐个字符地组合存储在纸带上的准备好的密钥与明文的字符以生成密文。接收者将再次应用密钥来取回明文。

1919 年，Vernam 为他的想法申请了专利（美国专利 1,310,719）。在 Vernam 的方法中，他使用了应用于消息位的二进制 XOR（异或）运算。我们将在第 1 章中更详细地研究包括 XOR 在内的二元运算。4.按照现代标准，要真正成为一次性密码本，密码需要两个属性。第一个是由名称暗示的：密钥只使用一次。使用特定密钥对消息进行加密后，该密钥将不再使用。这使得一次性便笺本非常安全，但对于正在进行的通信（例如电子商务中的一次相遇）来说也是非常不切实际的。第二个属性是密钥与消息一样长。这可以防止任何模式出现在密文中。值得注意的是，Vernam 还为其他三项密码发明申请了专利：美国专利 1,416,765；美国专利 1,584,749；和美国专利 1,613,686。

## 有限元方法代写

assignmentutor™作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

assignmentutor™您的专属作业导师
assignmentutor™您的专属作业导师