On Tue, 9 Oct 2001, Jose Nelson Amaral wrote:
[snip]
>ew think we found an error in the lab... exemplified after "Example",
you start with:
>
>-----------
>1| 0| 1| 0|
>-----------
^ ^
MSB LSB (of original input from KB_HEX = 10)
>
>But shouldn't it be:
>
>-----------
>0| 1| 0| 1|
>-----------
^ ^
MSB LSB (input bit order reversed)
this is just showing the reversal of the order of the bits. the key that
was pressed was 'A'. So, KB_HEX translates this to the hex number A,
binary '1010'. The first step to the encryption process is to reverse the
order of the bits, so we get '0101'. Now we proceed to encryption step 1,
"Expand and Permute the original bits" ("original" here means "original
bits in reverse order from step 0").
>
>??? I am getting alittle confused because of all the 'endian-ness'... but
>I am pretty sure that it is backwards because how you work with the b1's
>and B13's is contradictory... hard to explain because we have gone through
>it with our heads and we even managed to confuse ourselves.
>
"Oh, there it is...
...Then what the heck was that other piece of code we changed?"
This archive was generated by hypermail 2.1.3 : Wed Nov 21 2001 - 15:50:12 MST