Welcome Guest [Log In] [Register]
Viewing Single Post From: Announcement: Official Vigenère Tutorial
rot13 Oct 11 2005, 03:31 PM
Elite member
[ * * * * * ]
cows
Oct 11 2005, 03:21 PM
o.K. am i understanding this?

If i wanted to type my name would the finished code be:
Code:
 
 
CDEFGHIJKLMNOPQRSTUVWXYZAB
OPQRSTUVWXYZABCDEFGHIJKLMN
WXYZABCDEFGHIJKLMNOPQRSTUV
STUVWXYZABCDEFGHIJKLMNOPQR


Or am i getting this wrong?

If you wanted your name to be the keyword, you pretty much have it:

Code:
 

 ABCDEFGHIJKLMNOPQRSTUVWXYZ
 ----------------------------------------
 CDEFGHIJKLMNOPQRSTUVWXYZAB
 OPQRSTUVWXYZABCDEFGHIJKLMN
 WXYZABCDEFGHIJKLMNOPQRSTUV
 STUVWXYZABCDEFGHIJKLMNOPQR


Then to encrypt a message like "til the cows come home" you encrypt the first letter using the C line, the next letter using the O line, and so on. Here is the message with the line used to encrypt it written below:
Code:
 

TIL THE COWS COME HOME
COW SCO WSCO WSCO WSCO

so for line C, T is encrypted as V
for line O, I is encrypted as W
for line W, L is encrypted as H
for line S, T is encryptes as L,
for line C, H is encrypted as J
for line O, E is encrypted as S
...and so forth

The final encrypted message, with word breaks preserved, would be:
VWH LJS YGYG YGOS DGOS

Notice the repeating YGYG YG. That's an interesting thing. With Vigenere, encrypting C with a key of W is the same as encrypting W with a key of C. The word COWS is encrypted with a key of WSCO. So CO with a key of WS encrypts as YG. Likewise, WS with a key of CO also encrypts as YG.
Offline Profile Quote Post
Announcement: Official Vigenère Tutorial · News