Encryption/Programming Challange

[Th3_M4d_H4tt3r]

I hope this gets turned into an HTS mission, cuz' I have a little challenge for you guys, I made my own encryption in python using a number based "key".

here is the code I used to encrypt it:

Code: Select all

password=list("test123")

def encrypt(password):
   count = 0
   encrypted_password = ""
   for x in password:
      password[count] = x
      count = count+1
   for i in range(0, len(password)):
      try:
         encrypted_password = encrypted_password + password[i] + password[i+3]
         if encrypted_password+encrypted_password==password:
            break
      except:
         break
   print encrypted_password

encrypt(password)


this is my encrypted message:

Code: Select all

Y0o
u    efnuccrkyipntge dd_ipda sistw!o!r!d.  =T h"i"s
   mfeosrs axg ei nw apsa sesnwcorrydp:t
e   d    puassisnwgo rtdh[icso ucnotd]e :=

xd
e   f    ceonucnrty p=t (cpoausnstw+o1r
d   )f:o
r    cio uinnt  r=a n0g
e   (e0n,c rlyepnt(epda_spsawsosrwdo)r)d:
=       "t"r
y   :f
o   r       xe nicnr yppatsesdw_oprads:s
w   o   rpda s=s weonrcdr[ycpotuendt_]p a=s sxw
o   r   dc o+u npta s=s wcoorudn[ti+]1
+    fpoars siw oirnd [ria+n1g5e](
0   ,       liefn (epnacsrsywpotredd)_)p:a
s   s   wtorryd:+
e   n   c   reynpctreydp_tpeads_spwaosrsdw=o=rpda s=s weonrcdr:y
p   t   e   d   _bpraesaskw
o   r   de x+c eppats:s
w   o   r   db[rie]a k+
   pparsisnwto redn[cir+y1p5t]e
d   _   p   aisfs weonrcdr
y
petnecdr_yppats(spwaosrsdw+oerndc)


Try to reverse-engineer the code and post the message.

Good luck HTS!

[Tentra]

I don't understand your code.

What is the purpose of this:

Code: Select all

for x in password:
   password[count] = x
   count = count+1


Your code seems to try an generate a more secure password using "test123" as a seed, however, where is the data actually encrypted using the password?

Was the plaintext passed into the `encrypt` function which resulted in the ciphertext you posted?

[Th3_M4d_H4tt3r]

No, what I did is encrypted some plain-text; and posted the results; test123 what a test in the program. The program was original designed to recongnize a pattern (<- HINT), but it encrypted it instead.

[Goatboy]

I won't post the results, but apparently I "fucking did it!!!"

Looks like you didn't post the entire encrypted output though. Part of the message I deciphered was cut off (middle of line 12 of deciphered output) but I got the gist.

[Th3_M4d_H4tt3r]

Wow, good job! how did you decode it?

[Goatboy]

I looked at it for about 5 seconds and erased every other character. The repeated exclamation points and overall layout tipped me off right away.

[DrRoach]

Not a bad encryption figured most of it out from a glimpse just being a pain but I wouldn't recommended adding passwords in text as an encryption because people will always be able to figure it out especially in some cases where people have reading disorders like dyslexia for example it could just jump out at them but yeah cool encryption I like it

[mShred]

Lol, this was actually a little interesting. But Goatboy is right, after you look at it, you can basically depict it out. And looking at your script, you should be able to read what's going on.
I posted a little script to decrypt it below, as long as that's alright of course.

Code: Select all

<?php

        error_reporting(0);

        $t = str_split(file_get_contents('t.txt'),1);

        for($i=0; $i<(count($t)); $i++)
        {
                if((($i % 2) == 0) && (($t[$i] . $t[$i+1]) != '  ' ))
                {
                        echo($t[$i]);
                }
        }

        echo("\r\n");

?>


[Kataclysmic]

I am currently doing something in python to decrypt it, but I am compelled to tell you that the

Code: Select all

for x in password:
      password[count] = x
      count = count+1


is pointless and does not change the outcome of your program.

-- Wed Oct 09, 2013 11:30 pm --

I won't post the results, but apparently I "fucking did it!!!"

Looks like you didn't post the entire encrypted output though. Part of the message I deciphered was cut off (middle of line 12 of deciphered output) but I got the gist.

The reason it is cut off it because of the method of breaking the loop. Once it tries to do + password[i+3] when i+3 > len(password) it causes and error which breaks the loop and the message will not be encrypted from that point on giving only a partial message.

-- Thu Oct 10, 2013 12:26 am --

alright here is my code that I used to decrypt the message. very simple.

Code: Select all

def decrypt(password):
    decrypted_password = password[0::2]
    decrypted_password += password[-5]+password[-3]+password[-1]
    return "".join(decrypted_password)


[WallShadow]

sorry for necro, i just can't pass up a cryptography challenge just like that.

it was an easy vertical transposition cipher with a key of 2. an automatic transposition cracker picked it up in less than a minute. although the code formatting didn't go over well with the cracker