Using AES ( CBC ) Encryption in java with Client Server

//File : DesServer.java
//DesReceiver
//Developed by Malhar Vora
//Developed on : 9-5-2011
import java.io.*;
import java.net.*;
import java.util.*;
import java.math.*;
import javax.crypto.*;
import java.security.*;
import javax.crypto.spec.*;

public class DesServer
{

 public static void main(String []str)throws Exception
 {
    ServerSocket ss = new ServerSocket(5656);
    Socket s = null;
    InputStream is = null;
    ObjectInputStream ois = null;
    Frame f =null;
    
    while(true)
    {
    s=ss.accept();
    is = s.getInputStream();
    ois = new ObjectInputStream(is);
    f = (Frame)ois.readObject(); 
    
    System.out.println(decryptString(f.data,f.k,new IvParameterSpec(f.iv)));    
           
    break;
    }
    
    ois.close();
    is.close();
    s.close();
    ss.close();  
  
 }
 
  
 
 static String decryptString(String data,Key key,IvParameterSpec ivspec)throws Exception
 {
     KeyGenerator kg = KeyGenerator.getInstance("DES");
  kg.init(56);
  Cipher c = Cipher.getInstance("DES/CBC/PKCS5Padding");
  Key k = key;
  
  c.init(Cipher.DECRYPT_MODE,new SecretKeySpec("12345678".getBytes(),"DES"),ivspec);
  
  
  
  byte[] plaintext = c.doFinal(data.getBytes());
  
  return new String(plaintext);
 }
 
  
 
}

/******************************************************************/

//File : DesClient.java
//DesClient
//Developed by Malhar Vora
//Developed on : 9-5-2011
import java.io.*;
import java.net.*;
import java.util.*;
import java.math.*;
import javax.crypto.*;
import java.security.*;
import javax.crypto.spec.*;




public class DesClient
{
    static KeyGenerator kg = null;
 static Cipher c = null;
 static Key k = null;
 static byte[] ivector=null;
 public static void main(String []str)
 {
  
  String datatosend=null;
     try
  {
      datatosend = encryptString(getDataFromFile("Data.txt"));
   Frame f = new Frame(datatosend,k,ivector);
   
   
   
   sendFrame("localhost",5656,f);
    
  }
  catch(Exception e)
  {
   System.out.println(e);
  }
  
 }
 
 static String getDataFromFile(String filename) throws Exception 
 {
     String str="";
  Scanner sc  = new Scanner(new File(filename));
  while(sc.hasNextLine())
  {
   str=str + sc.nextLine();
  }
  sc.close();
  return str;
  
 }
 
 static String encryptString(String data) throws Exception
 {
     kg = KeyGenerator.getInstance("DES");
  kg.init(56);
  c = Cipher.getInstance("DES/CBC/PKCS5Padding");
  k = kg.generateKey();
  
    
  c.init(Cipher.ENCRYPT_MODE,new SecretKeySpec("12345678".getBytes(),"DES"));
  byte[] plaintext = data.getBytes();
  byte[] ciphertext = c.doFinal(plaintext);
  
  ivector = c.getIV();
          
  return new String(ciphertext);
  
 }
 
 static void sendFrame(String remoteaddress,int port,Frame f) throws Exception
 {
     Socket s = new Socket(remoteaddress,port);
  OutputStream os = s.getOutputStream();
  ObjectOutputStream ous = new ObjectOutputStream(os);
  
  ous.writeObject(f);
  
  ous.close();
  os.close();
  s.close();       
 
 }
 
  
 
 
 

}

/***********************************************************/

//File : Frame.java
//Frame Class
//Developed by Malhar Vora
//Developed on : 9-5-2011
import java.io.*;
import java.net.*;
import java.util.*;
import javax.crypto.*;
import java.security.*;
import javax.crypto.spec.*;

public class Frame implements Serializable
{
    
    String data;
    Key k;
 byte[] iv;

    Frame(String mydata,Key key,byte[] ivector)
    { 
  data=mydata;
  k = key;
  if(ivector==null)
  {
     iv = null;
  }
  else
  {
   iv = new byte[ivector.length];
   for(int i=0;i<ivector.length;i++)
   {
    iv[i]=ivector[i];
   }
  }
 }  

}

Browsing gmail using secure connection

Follow the simple steps given below :

Step 1 : Click on Settings option situated at top right corner of screen.

Step 2 : In General tab look for 5th option "Browser connection".

Step 3 : Click on Always use https option.

Step 4 : Save changes

After completing procedure you will see https://www.gmail.com instead of http://www.gmail.com. This indicates that you are browsing gmail on secure connection. It makes your connection encrypted by using SSL/TLS protocols so protects you from the eavesdropping and intercepting your data by someone for malicious purpose. 

You can also enable secure browsing in facebook. Read how to make facebook connection secure here