古典加密算法文档及代码.doc

计算机科学与技术学院 软件工程2班 20042170 宋鹏信息安全程序设计一一、实验目的：学习并掌握密码学基础中古典加密体制的一些主要方法。二、设计要求：编程实现移位密码、仿射密码、维吉尼亚密码和置换密码，要求如下：1、程序输入为明文和密钥（对于仿射密码应该检查密钥的合法性）；2、执行加密和解密过程；3、输出加密的密文和解密恢复的明文，并和开始输入的明文进行比较。三、设计步骤：程序在JAVA环境中实现，由于编程基础不够扎实可能程序没有明显的体现出面向对象的风格，期望老师见谅。1：首先构造基本的古典加密界面如图1.1 图1.12：然后添加界面所用到的组件和注册监听器。3：编写各个算法的加密和解密函数进行加密解密时的调用。四、以下分别是构造界面，添加组件及监听器和各个算法实现代码，分别都有标注import java.awt.*;import javax.swing.*;import java.awt.event.*;/*构造古典加密算法界面*/public class JMJM extends WindowAdapter implements ActionListener,ItemListenerLabel l1=new Label(输入:),l2=new Label(加密:),l3=new Label(解密:),l4=new Label(密钥:); JFrame f;TextField t1=new TextField(55),t2=new TextField(55),t3=new TextField(55),t4=new TextField(20);Button b1=new Button(加密),b2=new Button(解密),b3=new Button(清屏);Choice c1;Panel p1,p2,p3,p4,p5,p6,p7,p8,p9;public void display() f=new JFrame(加密算法 宋鹏 20042170 QQ348946154 );f.setSize(480,200);f.setLocation(200,140);f.setBackground(Color.lightGray);f.setLayout(new BorderLayout();tiajiazujian();f.setVisible(true);/*添加界面组件以及监听器*/public void tiajiazujian() c1=new Choice();c1.add(移位算法);c1.add(仿射算法);c1.add(维吉尼亚算法);c1.add(置换算法);c1.addItemListener(this);f.add(c1,North);p1=new Panel();p3=new Panel();f.add(p3,Center);p3.setLayout(new FlowLayout();p3.add(l1);p3.add(t1);p3.add(l2);p3.add(t2);p3.add(l3);p3.add(t3);p2=new Panel();f.add(p2,South);p2.setLayout(new GridLayout(1,5);p2.add(l4);p2.add(t4);p2.add(b1);p2.add(b2);p2.add(b3);b1.addActionListener(this);b2.addActionListener(this);b3.addActionListener(this);/*对应不同加密算法的按钮点击事件*/public void actionPerformed(ActionEvent e) if (e.getSource()=b3&c1.getSelectedIndex()=0)t1.setText( );t2.setText( );t3.setText( );if (e.getSource()=b1&c1.getSelectedIndex()=0)ywjiami();if(e.getSource()=b2&c1.getSelectedIndex()=0)ywjiemi();if(e.getSource()=b1&c1.getSelectedIndex()=1)fcjiami();if(e.getSource()=b2&c1.getSelectedIndex()=1)fcjiemi();if(e.getSource()=b1&c1.getSelectedIndex()=2)wjnyjiami();if(e.getSource()=b2&c1.getSelectedIndex()=2)wjnyjiemi();if(e.getSource()=b1&c1.getSelectedIndex()=3)zhjiami();if(e.getSource()=b2&c1.getSelectedIndex()=3)zhjiemi();public void itemStateChanged(ItemEvent e)/*移位加密算法*/public void ywjiami() String s1;String s2;char zifu; s1=t1.getText();s2=t4.getText();int a;a=Integer.parseInt(s2);zifu = s1.toCharArray(); for (int i = 0;izifu.length ;i+ ) zifui=(char)(zifui-97+a)%26)+97); String s3=new String(zifu); s3=s3.toUpperCase();t2.setText(s3); /*移位解密算法*/public void ywjiemi() String s1;String s2;char zifu; s1=t2.getText();s2=t4.getText();int a;a=Integer.parseInt(s2);zifu = s1.toCharArray(); for (int i = 0;izifu.length ;i+ ) zifui=(char)(zifui-97-a)%26)+97); String s3=new String(zifu); s3=s3.toLowerCase();t3.setText(s3);/*求最大公约数辗转相除法*/int gcd(int a, int b) int k = 0;do k = a%b; a = b; b = k;while(k!=0);return a;/*求模逆*/int Ni(int a, int b) int i = 0;while(a*(+i)%b!=1);return i;/*仿射加密算法*/public void fcjiami() int i=0, a=0, b=0, tmp;String s1;String s2;char zifu; s1=t1.getText();s2=t4.getText(); a=Integer.parseInt(s2)/10;b=Integer.parseInt(s2)%10;zifu = s1.toCharArray();/*如果输入密钥不合法则显示密钥错误*/if(gcd(a,26)!=1) String s3=new String();s3=密钥错误; t3.setText(s3);for(i=0; i96&zifui64&zifui91)zifui = (char)(a*(zifui-65)+b)%26+65);String s4=new String(zifu);t2.setText(s4);/*仿射解密算法*/public void fcjiemi() int i=0, a=0, b=0, tmp;String s1;String s2;char zifu; s1=t1.getText();s2=t4.getText();/*在密钥输入文本框中输入2位密钥首先转换成2位整数在利用/和算法求出2个合法密钥在进行计算*/ a=Integer.parseInt(s2)/10;b=Integer.parseInt(s2)%10;zifu = s1.toCharArray();for(i=0; i64&zifui91) tmp = Ni(a,26)*(zifui-65)-b);if(tmp0) zifui = (char)(tmp%26+26+97);else zifui = (char)(tmp%26+97); String s4=new String(zifu); t3.setText(s4);/*维吉尼亚加密算法*/public void wjnyjiami() int i,j,s=0;int k=0 ;String s1;String s2;char zifu,miyao; s1=t1.getText();s2=t4.getText();miyao =s2.toCharArray();zifu = s1.toCharArray();for(i=0; izifu.length; i+)zifui = (char)(zifui-97+(miyaok%miyao.length-97)%26+97);k+;String s3=new String(zifu);s3=s3.toUpperCase();t2.setText(s3);/*维吉尼亚解密算法*/public void wjnyjiemi() int i,j,k=0,tmp;String s1;String s2;char zifu,miyao; s1=t2.getText();s2=t4.getText();s1=s1.toLowerCase();miyao =s2.toCharArray();zifu = s1.toCharArray();/*解密算法中会出现减出负数的状况如果出现负数加26解决问题*/ for (i =0;izifu.length ;i+ ) tmp = (zifui-miyaok%(miyao.length); zifui=(char)(tmp+65); if (tmp0) zifui =(char)(tmp+65+26); k+; ;String s3=new String(zifu);s3=s3.toLowerCase();t3.setText(s3);/*置换加密算法*/public void zhjiami() int i,k=0,tmp;String s1;String s2;char zifu,miyao;s1=t1.getText();s2=t4.getText(); zifu=s1.toCharArray(); miyao =s2.toCharArray();char zifu1=new charzifu.length;int j=new intmiyao.length;/*将输入的密钥的ASC码减去字符0对应的ASC码得数相应密钥对应的整形数值存取在整型数组j中*/for(i=0;imiyao.length;i+)ji=miyaoi-48;for(i=0; izifu.length; i+) tmp = i/miyao.length; zifu1i =zifuji%miyao.length+(tmp*miyao.length)-1; ;String s3=new String(zifu1);s3=s3.toUpperCase();t2.setText(s3); /*置换解密算法*/public void zhjiemi() int i,k=0,tmp;String s1;String s2;char zifu,miyao;s1=t2.getText();s2=t4.getText(); zifu=s1.toCharArray(); miyao =s2.toCharArray();char zifu1=new charzifu.length;int j=new intmiyao.length;/*将输入的密钥的ASC码减去字符0对应的ASC码得数相应密钥对应的整形数值存取在整型数组j中*/for(i=0;imiyao.length;i+)ji=miyaoi-48; for(i=0; izifu.length; i+)tmp = i/miyao.length; zifu1ji%miyao.length+tmp*miyao.length-1 =zifui;String s3=new String(zifu1);s3=s3.toLowerCase();t3.setText(s3); public static void main(String arg)JMJM ob=new JMJM();ob.display(); 五、运行结果截图以下是四种算法的加密解密截图，分别按照教案所提供的正确明文和密文对应数据运行结果截图。1：移位密码加密移位密码解密2：仿射密码加密仿射密码解密仿射密码密钥输入错误3：维吉尼亚密码加密维吉尼亚密码解密4：置换密码加密置换密码解密总结：通过这次的编程作业对古典加密的四种