Encryption_DES_java.zip_Image Encryption_The First_honest matlab

/** * This demonstrates password-based encryption (PBE) using the * DES algorithm. As mentioned before, DES is not very secure, * but the SDK version used for this example does not support * other (stronger) PBE algorithms * * The text file "clear.txt" will be read, encrypted and written back * as "clear.txt.des". * * I've done all the "hardcoding" of the file names and password for * simplicity of discussion. * */ import java.io.*; import java.security.*; import javax.crypto.*; import javax.crypto.spec.*; import java.util.*; public class FileEncryptor { private static String filename; private static String password; private static FileInputStream inFile; private static FileOutputStream outFile; /** * Note: As with the pervious example, all kinds of exceptions * can be thrown in main. See the API documentation for each * method used. */ public static void main(String[] args) throws Exception { // File to encrypt. It does not have to be a text file! filename = "out.jpg"; // Password must be at least 8 characters (bytes) long String password = "abc123abc"; inFile = new FileInputStream(filename); outFile = new FileOutputStream("result.dat"); // Use PBEKeySpec to create a key based on a password. // The password is passed as a character array PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray()); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES"); SecretKey passwordKey = keyFactory.generateSecret(keySpec); // PBE = hashing + symmetric encryption. A 64 bit random // number (the salt) is added to the password and hashed // using a Message Digest Algorithm (MD5 in this example.). // The number of times the password is hashed is determined // by the interation count. Adding a random number and // hashing multiple times enlarges the key space. byte[] salt = new byte[8]; Random rnd = new Random(); rnd.nextBytes(salt); int iterations = 100; //Create the parameter spec for this salt and interation count PBEParameterSpec parameterSpec = new PBEParameterSpec(salt, iterations); // Create the cipher and initialize it for encryption. Cipher cipher = Cipher.getInstance("PBEWithMD5AndDES"); cipher.init(Cipher.ENCRYPT_MODE, passwordKey, parameterSpec); // Need to write the salt to the (encrypted) file. The // salt is needed when reconstructing the key for decryption. outFile.write(salt); // Read the file and encrypt its bytes. byte[] input = new byte[64]; int bytesRead; while ((bytesRead = inFile.read(input)) != -1) { byte[] output = cipher.update(input, 0, bytesRead); if (output != null) outFile.write(output); } byte[] output = cipher.doFinal(); if (output != null) outFile.write(output); inFile.close(); outFile.flush(); outFile.close(); } }