CODEWITHSUNDEEP
javaencryption
NoughT
NoughT

Reputation: 673

Decrypting image using java

I take this code from YouTube video.From this code I encrypt image correctly but could not decrypt that image.. Can anyone help me???

Encrypt code

        FileInputStream  file = new FileInputStream("src/image/A.jpg");
        FileOutputStream output = new FileOutputStream("src/image/AA.jpg");
        byte j[]="12345678".getBytes();
        SecretKeySpec kye = new SecretKeySpec(j,"DES");
        System.out.println(kye);
        Cipher enc = Cipher.getInstance("DES");
        enc.init(Cipher.ENCRYPT_MODE,kye);
        CipherOutputStream cos = new CipherOutputStream(output, enc);
        byte[] buf = new byte[1024];
        int read;
        while((read=file.read(buf))!=-1){
            cos.write(buf,0,read);
        }
        file.close();
        output.flush();
        cos.close();

Decrypt code

        FileInputStream  file = new FileInputStream("src/image/AA.jpg");
        FileOutputStream output = new FileOutputStream("src/image/AAA.jpg");
        byte j[]="12345678".getBytes();
        SecretKeySpec kye = new SecretKeySpec(j,"DES");
        System.out.println(kye);
        Cipher enc = Cipher.getInstance("DES");
        enc.init(Cipher.DECRYPT_MODE,kye);
        CipherOutputStream cos = new CipherOutputStream(output, enc);
        byte[] buf = new byte[1024];
        int read;
        while((read=file.read(buf))!=-1){
            cos.write(buf,0,read);
        }
        file.close();
        output.flush();
        cos.close();

thank you

Upvotes: 1

Views: 5524

Answers (1)

pbertsch
pbertsch

Reputation: 330

It is a relativly old post but I think I can help.

First, you should encode the Image into a ASCII representation. I would recommend Base64. It is much easier and less error attached when encrypting Base64. (Maybe not as strong but that depends on your needs)

The benefit of Base64 is the Alphabet it is using. No weird symbols at all.

1) Convert the image into a ByteArrayOutputStream by writing it with the ImageIO Class into one.

2) Encode the byte array into a Base64 String

3) Encrypt like you did above (Do not forget the flush).

4) Save bytes to new File. Delete old one.

Decrypt accordingly .....

Be aware, encoding into Base64 will blow up your memory and the file will be much bigger because of the Base64 AND the Encryption overhead.

Hope that helps !

Upvotes: 1

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