Going thru Second Chapter?

boy18nj · June 4th, 2011, 07:10 PM

I'm reading your book. So far good, but at some places I don't understand the technical information, moreover the code is written using bytes and hex code, which makes it difficult to see/understand the encrypted/decrypted message in action. Wasn't it possible to use Strings instead of bytes representing hexadecimal information? Why this has been made complicated for the readers, where String's could have been used.

dgh · June 4th, 2011, 11:25 PM

It's not possible to use Strings to cleanly represent encrypted data without first converting to Hex or some other codec like Base64, so the use of Hex is actually to simplify things. If you read the JavaDoc for java.lang.String concerning byte to String conversion and visa versa you will see why.

Regards,

David

boy18nj · June 5th, 2011, 09:07 AM

Thanks for reply.

So you mean encrypted data won't be nicely represented if we use like this

Doing this improves the readability and understanding of code, don't you think so?

Code:

String input = "hello this is second chapter input  example".
byte[] inputByte = input.getBytes();

        byte[]          input = new byte[] { 
                0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
                0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
                0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
        byte[]		    keyBytes = new byte[] { 
                0x01, 0x23, 0x45, 0x67, (byte)0x89, (byte)0xab, (byte)0xcd, (byte)0xef };
        byte[]		    ivBytes = new byte[] { 
                0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00 };

dgh · June 5th, 2011, 07:47 PM

Personally I would not have said so, but I guess that is a matter of opinion. What I can say is that been able to deal with Hex strings is an invaluable skill in both debugging and understanding most standards related to cryptography. From that point of view alone it is worth becoming comfortable with Hex as a format for data description.

Regards,

David