Didactic Feedback Cipher 2

gfoot · Post by **gfoot** » Wed Oct 15, 2008 10:54 am

Is this challenge really meant to have the same ciphertext as the previous one? The same answer doesn't work.

tails · Post by **tails** » Wed Oct 15, 2008 1:25 pm

This time I can't solve it either

Post by **adum** » Wed Oct 15, 2008 3:48 pm

whoops, fixed!

tails · Post by **tails** » Wed Oct 15, 2008 5:10 pm

adum wrote:whoops, fixed!

Thank you! I solved it. But it was very tough again!
The notable fact is that the sequence consists of odd number of characters.

the_impaler · Post by **the_impaler** » Thu Oct 16, 2008 6:52 am

Yeah, this is kind of a problem for me - why is it ending (or starting ? ) with half byte ?
Or it's Broken one again ?

Post by **adum** » Thu Oct 16, 2008 7:16 am

whoops, it's not meant to have an odd number or chars! sorry guys, i messed up again. it's fixed now...

this time it really boggles my mind that it got solved in a broken state. i had forgotten to mod by 256 and numbers were getting bigger than a byte.

sorry again,
adum

gfoot · Post by **gfoot** » Thu Oct 16, 2008 8:02 am

Yes, wow, nice one tails!

tails · Post by **tails** » Thu Oct 16, 2008 8:05 am

Sorry I should have pointed out the problem more clearly.

And please count me out next time when you validate your challenges.

the_impaler · Post by **the_impaler** » Fri Oct 17, 2008 9:34 pm

That was good, tails!
gfoot did a nice job too to bring "Start" challenge to discuss.
Didactic Feedback Cipher Long 2 has a typo in description - one of those "k" should be "x" I presume.

sabretooth · Post by **sabretooth** » Thu Aug 06, 2009 6:50 pm

great challenge once again adum.

tails, I take my hat off to you.

sabretooth

inQr · Post by **inQr** » Mon Mar 07, 2011 7:14 pm

Hi,

I think my algorithm is correct, but I only get gibberish. I tried to filter characters which ASCII values are between 0 and 150, but this leads to no result.

I already solved 'Didactic XOR Cipher 3' which is similar to this one. Does the plaintext looks like: your answer is '…'?

Mon Jun 27, 2011 9:57 pm

inQr wrote: I already solved 'Didactic XOR Cipher 3' which is similar to this one. Does the plaintext looks like: your answer is '…'?

No, it does not. And Didactic Feedback Cipher is actually more similar to this one. Just try to deduce n+1 from n and you'll get there

longxie · Post by **longxie** » Thu Jul 28, 2011 1:08 pm

Hi guys, Is there a mistake in this challenge? Why the length of HEX string is 379?

Thu Jul 28, 2011 2:00 pm

If I counted correctly, the given string has a length of 124 single characters, which results in 124/2 = 62 ASCII characters.

longxie · Post by **longxie** » Fri Jul 29, 2011 3:06 am

I'm sorry, I made a mistake.

That I have said is about the "Didactic Feedback Cipher Long 2"