insecure

Sep 9 2005, 05:38 PM

As long as we all understand it's just for laughs and learning. If you're hoping to earn a million from it, forget it. There's so much cool free stuff out there that's way better than anything we would be able to do ourselves. Twofish, Rijndael (AES), etc etc.

Code:

 

To make this system work you need 3 keywords.  keyword 1 and 3
should include numbers, keyword 2 can be alpha only.

For our example, lets pick
Keyword 1=rudolph13
Keyword 2=stinky
Keyword 3=elephant79


Use Keyword 1 to create a scrambled alphabet by removing any duplicate letters or numbers (none in this case) and writing the remaining alphabet, and digits 0-9 under the key.

RUDOLPH13
ABCEFGIJK
MNQSTVWXY
Z02456789

strip off by collums to obtain:
RAMZUBN0DCQ2OES4LFT5PGV6HIW71JX83KY9

put into 6*6 Square to obtain checkerboard. Label collumns and rows A-F


   A B C D E F  (key #1 checkerboard)
   -----------
A |r a m z u b
B |n 0 d c q 2
C |o e s 4 l f
D |t 5 p g v 6
E |h i w 7 1 j
F |x 8 3 k y 9

Do the same thing with keyword 3,

ELPHANT79   <-note we removed the duplicate e
BCDFGIJKM
OQRSUVWXY
Z01234568

EBOZLCQ0PDR1HFS2AGU3NIV4TJW57KX69MY8

   A B C D E F  (key #3 checkerboard)
   -----------
A |e b o z l c
B |q 0 p d r 1
C |h f s 2 a g  
D |u 3 n i v 4
E |t j w 5 7 k  
F |x 6 9 m y 8


To encrypt your message, we start with key #1 checkerboard.  Find each character from your message in the checkerboard and write down its row and collumn (in that order)

   A B C D E F  (key #1 checkerboard)
   -----------
A |r a m z u b
B |n 0 d c q 2
C |o e s 4 l f
D |t 5 p g v 6
E |h i w 7 1 j
F |x 8 3 k y 9

s  e  n  d  h  e  l  p  a  t  o  n  c  e   <-our secret message
CC BC AB CB AE BC EC CD BA AD AC AB DB BC  <-encrypted version

Now take keyword #2.  List your message under it horizontally.

4 5 1 3 2 6  <-alphabetical order of keyword #2
S T I N K Y  <-keyword #2
-----------
C C B C A B  <-our encrypted message from the previous step
C B A E B C
E C C D B A
A D A C A B
D B B C

Pull the message off by collumns, by alphabetical order of the keyword.  Repeat letters should count from left to right.  (so if you have two R's,the R to the left goes first, then the r to the right)

BACABABBACEDCCCCEADCBCDBBCAB  <-The new scrambled encrypted message!

Split this up into pairs and now use key #3 checkerboard to DECRYPT back from pairs into ordinary characters.

   A B C D E F   (key #3 checkerboard)
   -----------
A |e b o z l c
B |q 0 p d r 1
C |h f s 2 a g  
D |u 3 n i v 4
E |t j w 5 7 k  
F |x 6 9 m y 8

BA CA BA BB AC ED CC CC EA DC BC DB BC AB  <-from previous step
b  o  b  0  h  v  s  s  l  2  f  d  f  q   <-our new result

split result into 5 letter groups and there you go!
BOB0H VSSL2 FDFQ

To decrypt, reverse the entire process.

Use the key #3 checkerboard to translate into row/collumn letters

B  O  B  0  H  V  S  S  L  2  F  D  F  Q
ba ca ba bb ac ed cc cc ea dc bc db bc ab

Then count the total number of characters and divide by the number of letters in your second keyword.  From this you can figure out how many letters should be in each collumn, and how many collumns will be short one letter.  Put the character under the keyword in the order of the letters.

4 5 1 3 2 6
S T I N K Y
-----------
c c b c a b
c b a e b c
e c c d b a
a d a c a b
d b b c

yank back off by rows.  split into pairs and use the key #1 checkerboard to translate back into the original message!

cc bc ab cb ae bc ec cd ba ad ac ab db bc
s  e  n  d  h  e  l  p  a  t  o  n  c  e

send help at once!!!!!


Code:

 


RAMZUBN0DCQ2OES4LFT5PGV6HIW71JX83KY9
EBOZLCQ0PDR1HFS2AGU3NIV4TJW57KX69MY8
IAMZNBO0SDP1EFQ2CGT4UHV5RJW69KX73LY8
CAJV6RBKW7YDLX8PEMZ9TFN1OGQ20HS35IU4


Quote:

 

A appears in position 2 three times out of four (for these keys); M appears in position 3 twice; Z in pos 4 three times; B in position 5 twice; and so on

Quote:

 

Is this one dead in the water,

Quote:

 

do you think the implementation should adopt your suggested change in the method of generating the key, or stick to the original method?

Code:

 


To make this system work you need 3 keywords.
Keyword advice:
keyword 1 and 3 should include numbers.  Consider two words joined by a number, with at least one of the words not in a dictionary.
keyword 2 can be alpha only.

For our example, lets pick
Keyword 1=rudolph13amfiog
Keyword 2=stinky          
Keyword 3=elephant214kandar

Use Keyword 1 to create a scrambled alphabet by removing any duplicate letters or numbers from the key, write down the key, then under the key, write the remaining alphabet (leaving out all letters and digits in the key), using the following rule:

If the last character of the key is a letter:
 Start with the first letter after the last letter of the key.  Then, when you hit the end of the alphabet, put in the remaining digits from 0 to 9.  After the digits, start over at the begining of the alphabet and put in the rest of the letters until you get back to where you started.

If the last character of the key is a digit:
 Start with the first digit after the last digit in the key.  Then, when you hit the end of the digits (9), put in the remaining letters from A to Z.  After the letters, start over at the beginingof the digits and put in the rest of the digits until you get back to where you started.
 
Of course, it is possible that the arrangment of a keyword may force you to start at the begining of the alphabet or digits, in which case when you hit the end, there will not be any characters left at the begining to cycle back to.  This shouldn't be a problem since it just adds one more type of mixed alphabet to our list.

Once you have written down all 36 characters in the order specified by the above rules, strip them off by collums to obtained your mixed alphabet.

RUDOLPH13AMFIG
JKNQSTVWXYZ024
56789BCE

RJ5UK6DN7OQ8LS9PTBHVC1WE3XAYMZF0I2G4  <-stripped off by collumns


put into 6*6 Square to obtain checkerboard. Label collumns and rows A-F


   A B C D E F  (key #1 checkerboard)
   -----------
A |R J 5 U K 6
B |D N 7 O Q 8
C |L S 9 P T B
D |H V C 1 W E
E |3 X A Y M Z  
F |F 0 I 2 G 4  

Do the same thing with keyword 3,

ELPHANT214KDR  
SUVWXYZ035678
9BCFGIJMOQ

ES9LUBPVCHWFAXGNYITZJ20M13O45QK6D7R8

   A B C D E F  (key #3 checkerboard)
   -----------
A |E S 9 L U B
B |P V C H W F
C |A X G N Y I
D |T Z J 2 0 M
E |1 3 O 4 5 Q
F |K 6 D 7 R 8


To encrypt your message, we start with key #1 checkerboard.  Find each character from your message in the checkerboard and write down its row and collumn (in that order)

   A B C D E F  (key #1 checkerboard)
   -----------
A |R J 5 U K 6
B |D N 7 O Q 8
C |L S 9 P T B
D |H V C 1 W E
E |3 X A Y M Z  
F |F 0 I 2 G 4  

s  e  n  d  h  e  l  p  a  t  o  n  c  e   <-our secret message
BC FD BB AB AD FD AC DC CE EC DB BB CD FD  <-encrypted version

Now take keyword #2.  List your message under it horizontally.

4 5 1 3 2 6  <-alphabetical order of keyword #2
S T I N K Y  <-keyword #2
-----------
B C F D B B  <-our encrypted message from the previous step
A B A D F D
A C D C C E
E C D B B B
C D F D


Pull the message off by collumns, by alphabetical order of the keyword.  Repeat letters should count from left to right.  (so if you have two R's,the R to the left goes first, then the r to the right)

FADDFBFCBDDCBDBAAECCBCCDBDEB <-The new scrambled encrypted message!

Split this up into pairs and now use key #3 checkerboard to DECRYPT back from pairs into ordinary characters.

   A B C D E F  (key #3 checkerboard)
   -----------
A |E S 9 L U B
B |P V C H W F
C |A X G N Y I
D |T Z J 2 0 M
E |1 3 O 4 5 Q
F |K 6 D 7 R 8

FA DD FB FC BD DC BD BA AE CC BC CD BD EB  <-from previous step
B  2  F  I  Z  N  Z  S  1  G  X  J  Z  W   <-our new result

split result into 5 letter groups and there you go!
B2FIZ NZS1G XJZW

To decrypt, reverse the entire process.

Use the key #3 checkerboard to translate into row/collumn letters

B  2  F  I  Z  N  Z  S  1  G  X  J  Z  W
fa dd fb fc bd dc bd ba ae cc bc cd bd eb

Then count the total number of characters and divide by the number of letters in your second keyword.  From this you can figure out how many letters should be in each collumn, and how many collumns will be short one letter.  Put the character under the keyword in the order of the letters.

4 5 1 3 2 6
S T I N K Y
-----------
b c f d b b
a b a d f d
a c d c c e  
e c d b b b  
c d f d                        

yank back off by rows.  split into pairs and use the key #1 checkerboard to translate back into the original message!

bc fd bb ab ad fd ac dc ce ec db bb cd fd
s  e  n  d  h  e  l  p  a  t  o  n  c  e                                        

send help at once!!!!!

Of course, I wouldn't expect this to hold out against the NSA if they really wanted to read it, but I certainly wouldn't want to try and crack this code.
On the negative side, with three encryption steps (not counting creating the checkerboards) it's slow and vulnerable to errors.


"insecure"

 

I get the distinct impression that he is probably the best cryppie in this group so far

Donald

Sep 13 2005, 12:00 PM

"insecure"

 

I get the distinct impression that he is probably the best cryppie in this group so far

Well, I thank you kindly, but it's HIGHLY unlikely! I've been interested in cryptography since I was a little kid, but I've never gotten beyond very simple cryptanalysis. Revelation has written his own stego, you seem knowledgable, lots of other folks here probably understand more crypto than I do. Heck, PulsarSL says he's brand new at this and he's already cracked one of the challanges before I did.
Me, I don't even understand what an S Box IS. I'm definitely a rank amature.

Donald