I'm writing a steganography system which encrypt a text within an image - i decided that i want to encrypt the text as well before i embed it in the picture. The Steganography algorithm works with String input/output.
Due to my whim, i've been trying to use DES and AES algorithm but ran into the Exception above. i'll show for example the encryption/decryption methods of the AES algorithm:
public static byte[] encryptText(String plainText,SecretKey secKey) throws Exception{
// AES defaults to AES/ECB/PKCS5Padding in Java 7
Cipher aesCipher = Cipher.getInstance("AES");
aesCipher.init(Cipher.ENCRYPT_MODE, secKey);
byte[] byteCipherText = aesCipher.doFinal(plainText.getBytes());
return byteCipherText;}
public static String decryptText(byte[] byteCipherText, SecretKey secKey) throws Exception {
// AES defaults to AES/ECB/PKCS5Padding in Java 7
Cipher aesCipher = Cipher.getInstance("AES");
aesCipher.init(Cipher.DECRYPT_MODE, secKey);
byte[] bytePlainText = aesCipher.doFinal(byteCipherText);
return new String(bytePlainText);
}
And here is the calling (Encryption side):
//sending the text to encrypt using AES algorithm
byte[] cipherText = new AES_Algorithm().encrypt(messageDesc.getText(), key);
//converting into a String to encrypt using Steganography
newStringtoEncrypt = new String (cipherText);
And here is the calling (Decryption side) - THE EXCEPTION:
//AES encrypted String after the Steganography's decryption
String decMessage = dec.decode(path, name);
//converting the String to byte []
byte [] byteArray = decMessage.getBytes();
try{
//HERE IS WHERE I GET THE EXCEPTION
//sending the byte array to decryption
String original = AES_Algorithm().decrypt(byteArray, key);
Where is the problem?
The keys are similar and the byte arrays as well (i checked it by printing the sequence) - but i have been told that i can't use getBytes() in order to convert from String to byteArray when i intend to use AES/DES decryption algorithm.
