(A + B) x2 / 5.3 + 3.14 = 3000 for Mark

[markem]

okay, this has been a while and, based on the lack of posts, not generating much interest. Jordan started a killer puzzle with this one

Originally Posted by JE3146

Here's the hint

01101000 01110100 01110100 01110000 00111010 00101111 00101111 01110111 01110111 01110111 00101110 01100100 01101001 01101110 01101111 01100110 01101001 01101100 01101001 01100001 01110011 00101110 01100011 01101111 01101101 00101111 01100101 01101110 01100011 01110010 01111001 01110000 01110100 00101110 01101000 01110100 01101101



To discover the message in this blob...


169213212205216199218217112112

The secret to that one is 42

If you are intimately familiar with ASCII encoding (http://www.asciitable.com/) and can convert binary to hex on the fly (PM me if you want a crash course), then you will notice that the first set of binary (1s and 0s) quickly decodes to

http://www.dinofilias.com/encrypt.htm

(the double 't' gave it away for me)

and the resulting page wants a key and you paste in the encrypted string, press "decrypt" (bottom of page) and get Jordan's message. I'm assuming that the '42' is a Douglas Adams reference, but I could be wrong.

I replied with a simple bit of basic stego

Originally Posted by markem

I put your answer in this picture

which, if one gets the original picture (with stenography, we try to avoid well known pictures for this reason) one finds a series of bytes where the low order byte is often modified. This hints to a technique called "bit stealing" which, when followed to its conclusion (easiest if you get the GIF standard to see the relationship to sections ( http://www.dcs.ed.ac.uk/home/mxr/gfx/2d/GIF89a.txt)) yields the message "Cute, Jordan".

Then Jordan wanted something harder so I posted

Originally Posted by markem

Thought I would give you something trivial so as not to tax you.

Here is another pretty simple one. The key could be well known to you.

c157 35b4 0594 c185 5505 9575 84c1 c135
4584 25d5 c175 a495 e495 3554 9525 a5c1
35e4 c115 4584 c195 f5d7 85d5 1595 c154
45b4 c135 35a4 9584 c185 35a5 c1e4 9515
6321 c157 35b4 0594 c185 5505 9575 84c1
c135 f455 94f4 c195 c1d5 d5e4 c4f4 95e5
e4e4 c154 3584 d5c1 0505 b4c1 3545 85c1
8555 25c1 8435 6321 0063

Which is pretty simple (if you have the resources of the NSA behind you) but in reality is a trivial product cipher that uses one round similar to DES, with a trivial nibble manipulation at its core. I'll leave the final message as a problem for the interested.