Ty It Ns Practicals

// Program for implementing polycipher

package polyciipher;

import java.util.*;

public class PolyCiipher

{

public static void main(String[] args)

{

int[] j = new int[100];

int[] s = new int[100];

String test="";

// initialization of the Scanner class,handles input from user,can be found in the java.util.*; library.

// we are creating object "in" from the scanner and telling java that this will be System input

try{

Scanner in = new Scanner(System.in);

System.out.println("Enter the plain text(STRING SHOULD BE IN UPPERCASE AND DONT GIVE SPACE BETWEEN WORDS)::");

// next() is a method which gets the next string of text that a user types on the keyboard

test = in.nextLine();

for ( int i = 0; i < test.length(); ++i ) {

char c = test.charAt( i );// "c" holds the individual character of the string

s[i] = (int) c-65;

}

for(int i=0;i<test.length()-1;i++){

j[i+1]=s[i];

}

System.out.println("Enter the key::");

int k = Integer.parseInt(in.nextLine());

j[0]=k;

System.out.println();

System.out.println("The position of the character in the cipher text::");

for(int i=0;i<test.length();i++){

j[i]=j[i]+s[i];

j[i]=j[i]%26;

System.out.print(j[i]);

}


System.out.println("The cipher text::");

for(int i=0;i<test.length();i++){

char c=(char) (j[i]+65);

System.out.print(c);

}


}

catch(Exception er){

System.out.println("--YOU HAVE TYPE INVALID DATA--");

}

}

}

----------------------------------------------------------output---------------------------------------------------------------

Enter a string(STRING SHOULD BE IN ASCII AND DONT GIVE SPACE BETWEEN WORDS)::

ATTACKISTONIGHT

Enter the key::

12

1219121921218011712114130

MTMTCMSALHBVONA

BUILD SUCCESSFUL (total time: 16 seconds)

// Program for implementing Transposition ciphers

import java.awt.event.*;

import java.util.*;

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;

key = "tape";

message = "CRYPTOGRAPHYDEMO";

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]);

}


}


// 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(encryptedMessage);

System.exit(0);

}

}

OutPut

PCYR

RTGO

YAHP

ODME

PCYRRTGOYAHPODME

BUILD SUCCESSFUL (total time: 3 seconds)

// Program for implement Rail fence cipher in Java

// File Name: RailFence.java

import java.util.*;

class RailFenceBasic

{

int depth;

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

{

RailFenceBasic rf=new RailFenceBasic();

Scanner scn=new Scanner(System.in);

int depth;

String plainText,cipherText,decryptedText;

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);

decryptedText=rf.Decryption(cipherText, depth);

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

}

}

OUTPUT

Enter plain text:

railfencecipher

Enter depth for Encryption:

3

Encrypted text is:

rlnchafcieieepr

Decrypted text is:

railfencecipher

//Program for Implementing Columnar Cipher Transposition In Java:

import java.io.*;

public class columnar

{

` char arr[][],encrypt[][],decrypt[][],keya[],keytemp[];

public void creatematrixE(String s,String key,int row,int column)

{

arr=new char[row][column];

int k=0;

keya=key.toCharArray();

for(int i=0;i<row;i++)

{

for(int j=0;j<column;j++)

{

if(k<s.length())

{

arr[i][j]=s.charAt(k);

k++;

}

else

{

arr[i][j]=' ';

}

}

}

}

public void createkey(String key,int column)

{

keytemp=key.toCharArray();

for(int i=0;i<column-1;i++)

{

for(int j=i+1;j<column;j++)

{

if(keytemp[i]>keytemp[j])

{

char temp=keytemp[i];

keytemp[i]=keytemp[j];

keytemp[j]=temp;

}

}

}

}

public void creatematrixD(String s,String key,int row,int column)

{

arr=new char[row][column];

int k=0;

keya=key.toCharArray();

for(int i=0;i<column;i++)

{

for(int j=0;j<row;j++)

{

if(k<s.length())

{

arr[j][i]=s.charAt(k);

k++;

}

else

{

arr[j][i]=' ';

}

}

}

}

public void encrypt(int row,int column)

{

encrypt=new char[row][column];


{


{

if(keya[i]==keytemp[j])

{

for(int k=0;k<row;k++)

{

encrypt[k][j]=arr[k][i];

}

keytemp[j]='?';

break;

}

}

}

}

public void decrypt(int row,int column)

{

decrypt=new char[row][column];


{


{

if(keya[j]==keytemp[i])

{

for(int k=0;k<row;k++)

{

decrypt[k][j]=arr[k][i];

}

keya[j]='?';

break;

}

}

}

}

public void resultE(int row,int column,char arr[][])

{

System.out.println("Result:");


{

for(int j=0;j<row;j++)

{

System.out.print(arr[j][i]);

}

}

}

public void resultD(int row,int column,char arr[][])

{

System.out.println("Result:");

for(int i=0;i<row;i++)

{


{

System.out.print(arr[i][j]);

}

}

}

public static void main(String args[])throws IOException

{

int row,column,choice;

columnar obj=new columnar();

BufferedReader in=new BufferedReader(new InputStreamReader(System.in));

System.out.println("Menu:\n1) Encryption\n2) Decryption");

choice=Integer.parseInt(in.readLine());

System.out.println("Enter the string:");

String s=in.readLine();

System.out.println("Enter the key:");

String key=in.readLine();

row=s.length()/key.length();

if(s.length()%key.length()!=0)

row++;

column=key.length();

switch(choice)

{

case 1: obj.creatematrixE(s,key,row,column);

obj.createkey(key,column);

obj.encrypt(row,column);

obj.resultE(row,column,obj.encrypt);

break;

case 2: obj.creatematrixD(s,key,row,column);

obj.createkey(key,column);

obj.decrypt(row,column);

obj.resultD(row,column,obj.decrypt);

break;

}

}

}

//Program for implementing Diff hellman alogorithm

public static void createKey()throws Exception

{

KeyPairGenerator kpg = KeyPairGenerator.getInstance("DiffieHellman");

kpg.initialize(512);

KeyPair kp = kpg.generateKeyPair();

KeyFactory kfactory = KeyFactory.getInstance("DiffieHellman");

DHPublicKeySpec kspec = (DHPublicKeySpec) kfactory.getKeySpec(kp.getPublic(), DHPublicKeySpec.class);

}

public static void createSpecificKey(BigInteger p,BigInteger g)throws Exception

{

KeyPairGenerator kpg = KeyPairGenerator.getInstance("DiffieHellman");

DHParameterSpec param = new DHParameterSpec(p,g);

kpg.initialize(param);

KeyPair kp = kpg.generateKeyPair();

KeyFactory kfactory = KeyFactory.getInstance("DiffieHellman");

DHPublicKeySpec kspec = (DHPublicKeySpec) kfactory.getKeySpec(kp.getPublic(), DHPublicKeySpec.class);

}

static boolean isPrime(long n)

{

if (n%2 == 0)

{

return false;

}

for(int i = 3 ; i*i<=n;i+=2)

{

if(n%i==0)

return false;

}

return true;

}

public static void main(String [] args) throws Exception

{

Random randomGenerator = new Random();

long pValue = randomGenerator.nextInt(1000000);

long gValue = randomGenerator.nextInt(100000);

long correctPValue;

boolean checkPrime = isPrime(pValue);

System.out.println("the number generated is "+pValue);

System.out.println(checkPrime);

while(checkPrime == false)

{

long pValue2 = randomGenerator.nextInt(1000000);

boolean checkPrimeInLoop = isPrime(pValue2);

//System.out.println("value in loop is "+pValue2);

if(checkPrimeInLoop == true)

{

pValue=pValue2;

break;

}

}

long checkSP = (pValue*2)+1;

boolean checkSafePrime = isPrime(checkSP);

//System.out.println(checkSafePrime);

while(checkSafePrime==false)

{

long pValue3=randomGenerator.nextInt(1000000);

boolean checkPrimeInLoop = isPrime(pValue3);

long pValue5=(pValue3*2)+1;

//boolean checkSafePrimeInLoop = isPrime(pValue4);

boolean checkSafePrime2InLoop = isPrime(pValue5);

if(checkSafePrime2InLoop == true && checkPrimeInLoop == true)

{

pValue=pValue3;

break;

}

}

System.out.println("the safe prime is"+pValue);//safe prime

while(gValue>pValue)

{

long gValue2=randomGenerator.nextInt(100000);

if(gValue2<pValue)

{

gValue=gValue2;

break;

}

}

long getDivisor = (pValue-1)/2;

BigInteger bi1,bi2,bi3,bi4;

bi1=BigInteger.valueOf(getDivisor);

bi2 = BigInteger.valueOf(pValue);

bi3 = BigInteger.valueOf(gValue);

bi4= bi3.modPow(bi1,bi2);

long calculatedValue = bi4.longValue();

while(calculatedValue == 1)

{

long gValue3=randomGenerator.nextInt(100000);

long getDivisorInLoop = (pValue-1)/2;

BigInteger bi5,bi6,bi7,bi8;

bi5=BigInteger.valueOf(getDivisorInLoop);

bi6 = BigInteger.valueOf(pValue);

bi7 = BigInteger.valueOf(gValue3);

bi8= bi7.modPow(bi5,bi6);

long calculatedValueInLoop = bi8.longValue();

System.out.println(calculatedValueInLoop);

if(calculatedValueInLoop!=1)

{

gValue=gValue3;

break;

}

}

BigInteger generatorValue,primeValue;

generatorValue = BigInteger.valueOf(gValue);

primeValue = BigInteger.valueOf(pValue);

createKey();

int bitLength=512;

createSpecificKey(generatorValue,primeValue);

// Program for Implementing RC4 Alogorithm

import java.io.*;class rc4{public static void main(String args[])throws IOException{int temp=0;String ptext;String key;int s[]=new int[256];int k[]=new int[256];DataInputStream in=new DataInputStream(System.in);System.out.print("\nENTER PLAIN TEXT\t");ptext=in.readLine();System.out.print("\n\nENTER KEY TEXT\t\t");key=in.readLine();char ptextc[]=ptext.toCharArray();char keyc[]=key.toCharArray();int cipher[]=new int[ptext.length()];int decrypt[]=new int[ptext.length()];

int ptexti[]=new int[ptext.length()];int keyi[]=new int[key.length()];for(int i=0;i<ptext.length();i++){ptexti[i]=(int)ptextc[i];}for(int i=0;i<key.length();i++){keyi[i]=(int)keyc[i];}for(int i=0;i<255;i++){s[i]=i;k[i]=keyi[i%key.length()];}int j=0;for(int i=0;i<255;i++){j=(j+s[i]+k[i])%256;temp=s[i];

s[i]=s[j];s[j]=temp;}int i=0;j=0;int z=0;for(int l=0;l<ptext.length();l++){i=(l+1)%256;j=(j+s[i])%256;temp=s[i];s[i]=s[j];s[j]=temp;z=s[(s[i]+s[j])%256];cipher[l]=z^ptexti[l];decrypt[l]=z^cipher[l];}System.out.print("\n\nENCRYPTED:\t\t");display(cipher);System.out.print("\n\nDECRYPTED:\t\t");display(decrypt);}

static void display(int disp[]){char convert[]=new char[disp.length];for(int l=0;l<disp.length;l++){convert[l]=(char)disp[l];System.out.print(convert[l]);}}}

Out Put

RC4 encryption algorithm Program Output :

ENTER PLAIN TEXT RC4 PROGRAM

ENTER KEY TEXT A

ENCRYPTED: ??-??±?µFJ|

DECRYPTED: RC4 PROGRAM

// Program for Implementing RC5 Alogorithm

mport javax.swing.*;import java.util.io.*;public class Rc5{private int[] s;private int[] l;private int b, u, t, c;private byte[] key;private int rounds;public Rc5(){String str = "tallwalkers";key = GetKeyFromString(str);rounds = 16;b = (int)key.length;u = 4;t = (int)(34);c = 12 / u;s = new int[34];l = new int[12];GenerateKey(key, rounds);}

public Rc5(String password, int round){key = GetKeyFromString(password);rounds = round;b = (int)key.length;u = 4;t = (int)(2 * rounds + 2);c = Math.max(b, 1) / u;s = new int[2 * rounds + 2];l = new int[key.length];GenerateKey(key, rounds);}

public Rc5(byte[] password, int round){

rounds = round;key = password;b = (int)password.length;u = 4;t = (int)(2 * rounds + 2);c = Math.max(b, 1) / u;s = new int[2 * rounds + 2];l = new int[password.length];GenerateKey(key, rounds);}

private int leftRotate(int x, int offset){int t1, t2;t1 = x >> (32 - offset);t2 = x << offset;return t1 | t2;}private int RightRotate(int x, int offset){int t1, t2;t1 = x << (32 - offset);t2 = x >> offset;return t1 | t2;}private void Encode(RefObject<Integer> r1, RefObject<Integer> r2, int rounds){r1.argvalue = r1.argvalue + s[0];r2.argvalue = r2.argvalue + s[1];for (int i = 1; i <= rounds; i++){r1.argvalue = leftRotate(r1.argvalue ^ r2.argvalue, (int)r2.argvalue) + s[2 * i];r2.argvalue = leftRotate(r2.argvalue ^ r1.argvalue, (int)r1.argvalue) + s[2 * i + 1];}}private void Decode(RefObject<Integer> r1, RefObject<Integer> r2, int rounds){for (int i = rounds; i >= 1; i--){r2.argvalue = (RightRotate(r2.argvalue - s[2 * i + 1], (int)r1.argvalue)) ^ r1.argvalue;r1.argvalue = (RightRotate(r1.argvalue - s[2 * i], (int)r2.argvalue)) ^ r2.argvalue;}

r2.argvalue = r2.argvalue - s[1];r1.argvalue = r1.argvalue - s[0];}

private void GenerateKey(byte[] key, int rounds){int P32 = Integer.parseInt("b7e15163", System.Globalization.NumberStyles.HexNumber);int Q32 = Integer.parseInt("9e3779b9", System.Globalization.NumberStyles.HexNumber);for (int i = key.length - 1; i >= 0; i--){l[i] = leftRotate((int)i, 8) + key[i];}s[0] = P32;for (int i = 1; i <= t - 1; i++){s[i] = s[i - 1] + Q32;}int ii, jj;ii = jj = 0;int x, y;x = y = 0;int v = 3 * Math.max(t, c);for (int counter = 0; counter <= v; counter++){x = s[ii] = leftRotate((s[ii] + x + y), 3);y = l[jj] = leftRotate((l[jj] + x + y), (int)(x + y));ii = (ii + 1) % t;jj = (jj + 1) % c;}}private byte[] GetKeyFromString(String str){char[] mykeyinchar = str.toCharArray();byte[] mykeyinbytes = new byte[mykeyinchar.length];for (int i = 0; i < mykeyinchar.length; i++){mykeyinbytes[i] = (byte)mykeyinchar[i];}return mykeyinbytes;}

public final void Encrypt(FileStream streamreader, FileStream streamwriter)

{int r1, r2;System.IO.BinaryReader br = new System.IO.BinaryReader(streamreader);System.IO.BinaryWriter bw = new System.IO.BinaryWriter(streamwriter);long filelength = streamreader.getLength();while (filelength > 0){try{r1 = br.ReadUInt32();try{r2 = br.ReadUInt32();}catch (java.lang.Exception e){r2 = 0;}}catch (java.lang.Exception e2){r1 = r2 = 0;}

RefObject<Integer> tempRefObject = new RefObject<Integer>(r1);RefObject<Integer> tempRefObject2 = new RefObject<Integer>(r2);Encode(tempRefObject, tempRefObject2, rounds);r1 = tempRefObject.argvalue;r2 = tempRefObject2.argvalue;bw.Write(r1);bw.Write(r2);filelength -= 8;}streamreader.close();streamwriter.close();}public final void Decrypt(FileStream streamreader, FileStream streamwriter){int r1, r2;System.IO.BinaryReader br = new System.IO.BinaryReader(streamreader);System.IO.BinaryWriter bw = new System.IO.BinaryWriter(streamwriter);long filelength = streamreader.getLength();

while (filelength > 0){try{r1 = br.ReadUInt32();r2 = br.ReadUInt32();RefObject<Integer> tempRefObject = new RefObject<Integer>(r1);RefObject<Integer> tempRefObject2 = new RefObject<Integer>(r2);Decode(tempRefObject, tempRefObject2, rounds);r1 = tempRefObject.argvalue;r2 = tempRefObject2.argvalue;if (!(r1 == 0 && r2 == 0 && (filelength - 8 <= 0))){bw.Write(r1);bw.Write(r2);}if (r2 == 0 && (filelength - 8 <= 0)){bw.Write(r1);}filelength -= 8;}catch (java.lang.Exception e){JOptionPane.showConfirmDialog(null, "May be U try to decrypt an normal file (plain file)", "Error",

JOptionPane.DEFAULT_OPTION, JOptionPane.ERROR_MESSAGE);return;}}streamreader.close();streamwriter.close();}

}

// Program for RSA public key encryption algorithm implementation.

import java.math.BigInteger;

import java.security.SecureRandom;

public class RSA {

private BigInteger n, d, e;

private int bitlen = 1024;

/** Create an instance that can encrypt using someone elses public key. */

public RSA(BigInteger newn, BigInteger newe) {

n = newn;

e = newe;

}

/** Create an instance that can both encrypt and decrypt. */

public RSA(int bits) {

bitlen = bits;

SecureRandom r = new SecureRandom();

BigInteger p = new BigInteger(bitlen / 2, 100, r);

BigInteger q = new BigInteger(bitlen / 2, 100, r);

n = p.multiply(q);

BigInteger m = (p.subtract(BigInteger.ONE)).multiply(q

.subtract(BigInteger.ONE));

e = new BigInteger("3");

while (m.gcd(e).intValue() > 1) {

e = e.add(new BigInteger("2"));

}

d = e.modInverse(m);

}

/** Encrypt the given plaintext message. */

public synchronized String encrypt(String message) {

return (new BigInteger(message.getBytes())).modPow(e, n).toString();

}

/** Encrypt the given plaintext message. */

public synchronized BigInteger encrypt(BigInteger message) {

return message.modPow(e, n);

}

/** Decrypt the given ciphertext message. */

public synchronized String decrypt(String message) {

return new String((new BigInteger(message)).modPow(d, n).toByteArray());

}

/** Decrypt the given ciphertext message. */

public synchronized BigInteger decrypt(BigInteger message) {

return message.modPow(d, n);

}

/** Generate a new public and private key set. */

public synchronized void generateKeys() {

SecureRandom r = new SecureRandom();

BigInteger p = new BigInteger(bitlen / 2, 100, r);

BigInteger q = new BigInteger(bitlen / 2, 100, r);

n = p.multiply(q);

BigInteger m = (p.subtract(BigInteger.ONE)).multiply(q

.subtract(BigInteger.ONE));

e = new BigInteger("3");

while (m.gcd(e).intValue() > 1) {

e = e.add(new BigInteger("2"));

}

d = e.modInverse(m);

}

/** Return the modulus. */

public synchronized BigInteger getN() {

return n;

}

/** Return the public key. */

public synchronized BigInteger getE() {

return e;

}

/** Trivial test program. */

public static void main(String[] args) {

RSA rsa = new RSA(1024);

String text1 = "Yellow and Black Border Collies";

System.out.println("Plaintext: " + text1);

BigInteger plaintext = new BigInteger(text1.getBytes());

BigInteger ciphertext = rsa.encrypt(plaintext);

System.out.println("Ciphertext: " + ciphertext);

plaintext = rsa.decrypt(ciphertext);

String text2 = new String(plaintext.toByteArray());

System.out.println("Plaintext: " + text2);

}

}

//Write a program to encrypt input string by using Blowfish algorithm

//Blowfish algorithm

// Example program for Blowfish algorithm in java

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.swing.JOptionPane;

public class BlowfishCipher {

public static void main(String[] args) throws Exception {

KeyGenerator keygen = KeyGenerator.getInstance("Blowfish");

// create a key

SecretKey secretkey = keygen.generateKey();

Cipher cip = Cipher.getInstance("Blowfish");

// initialise cipher to with secret key

cip.init(Cipher.ENCRYPT_MODE, secretkey);

String inputText = JOptionPane.showInputDialog(" Give Input: ");

byte[] encrypted = cip.doFinal(inputText.getBytes());

cip.init(Cipher.DECRYPT_MODE, secretkey);

byte[] decrypted = cip.doFinal(encrypted);

JOptionPane.showMessageDialog(JOptionPane.getRootFrame(),

"encrypted : " + new String(encrypted) + "\n" +

"decrypted : " + new String(decrypted));

System.exit(0);

}

}

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Ty It Ns Practicals