Sin/RailFenceCipher.java at master · catvatar/Sin · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;
class RailFenceBasic{
    String Encryption(String plainText,int depth)throws Exception
    {
        int r=depth,len=plainText.length();
        int c=len/depth;
        char mat[][]=new char[r][c];
        int k=0;

        String cipherText="";

        for(int i=0;i< c;i++)
        {
            for(int j=0;j< r;j++)
            {
                if(k!=len)
                    mat[j][i]=plainText.charAt(k++);
                else
                    mat[j][i]='X';
            }
        }
        for(int i=0;i< r;i++)
        {
            for(int j=0;j< c;j++)
            {
                cipherText+=mat[i][j];
            }
        }
        return cipherText;
    }


    String Decryption(String cipherText,int depth)throws Exception
    {
        int r=depth,len=cipherText.length();
        int c=len/depth;
        char mat[][]=new char[r][c];
        int k=0;

        String plainText="";


        for(int i=0;i< r;i++)
        {
            for(int j=0;j< c;j++)
            {
                mat[i][j]=cipherText.charAt(k++);
            }
        }
        for(int i=0;i< c;i++)
        {
            for(int j=0;j< r;j++)
            {
                plainText+=mat[j][i];
            }
        }

        return plainText;
    }
}

class RailFence {
    public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Ceaser Cipher\n To Encrypt given plain text enter 1\n To Decrypt given cipher text enter 2");
        int n = Integer.parseInt(br.readLine());

        RailFenceBasic rf = new RailFenceBasic();
        Scanner scn = new Scanner(System.in);
        int depth;

        String plainText, cipherText, decryptedText;

        if (n == 1) {
            System.out.println("Enter plain text:");
            plainText = scn.nextLine();

            System.out.println("Enter depth for Encryption:");
            depth = scn.nextInt();

            cipherText = rf.Encryption(plainText, depth);
            System.out.println("Encrypted text is:\n" + cipherText);
        } else {
            System.out.println("Enter Cipher text:");
            cipherText = scn.nextLine();

            System.out.println("Enter depth for Encryption:");
            depth = scn.nextInt();

            decryptedText = rf.Decryption(cipherText, depth);

            System.out.println("Decrypted text is:\n" + decryptedText);
        }
    }
}