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transposition cipher in java

Hungry Hippopotamus answered on November 15, 2022 Popularity 3/10 Helpfulness 4/10

answer transposition cipher in java

related transposition cipher with key java code

transposition cipher in java

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/*
   authors by hafiq
   
   not very efficient algo for columnar transpose..LOL..
   
   any expert can advise me to improve this code...tq..
*/
import java.util.*;
import java.io.*;
import java.lang.*;

public class columnarTranspose {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String line = System.getProperty("line.separator");
        scan.useDelimiter(line);

        System.out.print("1. Encryt 2.Decrypt : ");
        int option = scan.nextInt();
        switch (option) {
            case 1:
                System.out.print("Enter String:");
                String text = scan.next();

                System.out.print("Enter Key:");
                String key = scan.next();

                System.out.println(encryptCT(key, text).toUpperCase());
                break;
            case 2:
                System.out.print("Enter Encrypted String:");
                text = scan.next();

                System.out.print("Enter Key:");
                key = scan.next();

                System.out.println(decryptCT(key, text));
                break;
            default:
                break;
        }
    }

    public static String encryptCT(String key, String text) {
        int[] arrange = arrangeKey(key);

        int lenkey = arrange.length;
        int lentext = text.length();

        int row = (int) Math.ceil((double) lentext / lenkey);

        char[][] grid = new char[row][lenkey];
        int z = 0;
        for (int x = 0; x < row; x++) {
            for (int y = 0; y < lenkey; y++) {
                if (lentext == z) {
                    // at random alpha for trailing null grid
                    grid[x][y] = RandomAlpha();
                    z--;
                } else {
                    grid[x][y] = text.charAt(z);
                }

                z++;
            }
        }
        String enc = "";
        for (int x = 0; x < lenkey; x++) {
            for (int y = 0; y < lenkey; y++) {
                if (x == arrange[y]) {
                    for (int a = 0; a < row; a++) {
                        enc = enc + grid[a][y];
                    }
                }
            }
        }
        return enc;
    }

    public static String decryptCT(String key, String text) {
        int[] arrange = arrangeKey(key);
        int lenkey = arrange.length;
        int lentext = text.length();

        int row = (int) Math.ceil((double) lentext / lenkey);

        String regex = "(?<=\\G.{" + row + "})";
        String[] get = text.split(regex);

        char[][] grid = new char[row][lenkey];

        for (int x = 0; x < lenkey; x++) {
            for (int y = 0; y < lenkey; y++) {
                if (arrange[x] == y) {
                    for (int z = 0; z < row; z++) {
                        grid[z][y] = get[arrange[y]].charAt(z);
                    }
                }
            }
        }

        String dec = "";
        for (int x = 0; x < row; x++) {
            for (int y = 0; y < lenkey; y++) {
                dec = dec + grid[x][y];
            }
        }

        return dec;
    }

    public static char RandomAlpha() {
        //generate random alpha for null space
        Random r = new Random();
        return (char)(r.nextInt(26) + 'a');
    }

    public static int[] arrangeKey(String key) {
        //arrange position of grid
        String[] keys = key.split("");
        Arrays.sort(keys);
        int[] num = new int[key.length()];
        for (int x = 0; x < keys.length; x++) {
            for (int y = 0; y < key.length(); y++) {
                if (keys[x].equals(key.charAt(y) + "")) {
                    num[y] = x;
                    break;
                }
            }
        }

        return num;
    }

}

Popularity 3/10 Helpfulness 4/10 Language java

Source: programmingcode4life.blogspot.com

Tags: java

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Contributed on Nov 15 2022

Hungry Hippopotamus

0 Answers Avg Quality 2/10

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transposition cipher with key java code

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import java.util.*;
import java.util.Scanner;  // needed for Scanner

public class transpositionCipher
{

public static void main(String args[]) 
{
String key;
String message;
String encryptedMessage; 
// Letters in the x-axis
int x=0; 
// Letters in the y-axis
int y=0; 


// Prompt the user
System.out.print( "Type your Key : " );


// Read a line of text from the user.

Scanner scan = new Scanner(System.in);
key = scan.nextLine();

// Display the input back to the user.
System.out.println( "Your Key is " + key );


//Prompt the user
System.out.print( "Type your Message : " );


//Read a line of text from the user.
message = scan.nextLine();

//Display the input back to the user.
System.out.println( "Your Message is " + message );



encryptedMessage = "";

// To set the temp as [x][y]
char temp[][]=new char [key.length()][message.length()];
char msg[] = message.toCharArray();
// To populate the array
x=0;
y=0;
// To convert the message into an array of char
for (int i=0; i< msg.length;i++)
{
temp[x][y]=msg[i];
if (x==(key.length()-1)) 
{
x=0;
y=y+1;
} // Close if 
else 
{
x++;
}
} // Close for loop

// To sort the key
char t[]=new char [key.length()];
t=key.toCharArray();
Arrays.sort(t);

for (int j=0;j<y;j++)
{
for (int i=0;i<key.length();i++)
{
System.out.print(temp[i][j]);
}
System.out.println();
}

System.out.println();

// To print out row by row (i.e. y)
for (int j=0;j<y;j++){ 
// To compare the the sorted Key with the key
// For char in the key
for (int i=0;i<key.length();i++){ 
int pos=0;
// To get the position of key.charAt(i) from sorted key
for (pos=0;pos<t.length;pos++){ 
if (key.charAt(i)==t[pos]){ 
// To break the for loop once the key is found
break;
}
}
System.out.print(temp[pos][j]);
encryptedMessage+=temp[pos][j];
}
System.out.println();
}

System.out.println(encryptedMessage);
System.exit(0);
}
}

Popularity 3/10 Helpfulness 4/10 Language java

Source: stackoverflow.com

Tags: java key

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Contributed on Nov 15 2022

Mushy Mole

0 Answers Avg Quality 2/10

transposition cipher in java

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