Emu's Encryption Tool Files

#### Emu's Encryption Tool ####
########### Readme ############


1. Whats this tool about?
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Emu's Encryption Tool is an application that encrypts text using polyalphabetic methods used in the middle ages. 
Because there are no mathematical functions or formulas the encrypted texts can't be cracked using bruteforce attacks or
other password cracking methods used in IT security. The texts are encrypted with random codes and fixed passwords but 
can also be used as an One-Time-Pad (OTP) which uses extreme long random passwords and codes and is impossible to encrypt.


2. How to use this tool
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For using this tool you first need a sender and a receiver. Both need the same codetable, so one of them should create one
using the "Random" option right below the codetable and save it to a file. All senders and receivers need to have the same
codetable! You don't need to change the codetable very often so you can keep the codefile and use it for every encryption.
When this step is done the sender has to set up a password and can type any text in the area upper left. With a click on
"Encrypt" the encrypted text appears in the lower text area. This text can now be sent to all receivers. Of course they need
to know the password too. The password should be changed quite often because its the key to decrypt the text. It's not
necessary to change it with every encryption. A good way is to use one password a day.
When the receivers get the encrypted text, they just have to paste it in the text area on the lower left, type in the password,
choose the right codetable and press "decrypt". The decrypted text appears in the text area on the upper left.
That's it.

Remember: The longer the password the better the encryption. An One-Time-Pad (OTP) is a password that is extreme long (2048 signs
in this case) and have no repeats in it.


3. How is it working?
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The encryption process is a polyalphabetic substitution using a 2D codetable and a password. You can easily encrypt texts
the same way just with pen and paper, it would just take a bit longer. For an example we encrypt the sample sentence
"The quick brown fox jumps over the lazy dog".
We use the following codetable:

   A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
   --------------------------------------------------- 
A| G S X J P V S X U Z N C J I N M Y H L E H G H L I A
B| D X R W X X L H X C R K Z A D X T V W V X S R Q J B
C| F M W U A O F D W D P I B P Z W D B Z I C W M X N L
D| I A E S Z M N K E G V Y D F X O Z A J M U D B R R W
E| K Z M V L J E P A O W R Q Z Y T E O Q F N C E W T Q
F| T Q S Y Q P K R Z F A L K Q M Z A Z Y W V B Z G U E
G| L G O M S K R Y T E K P V J R Q I S V B T N N F B S
H| U W P O E H B I M N O G T K S D K T R H S V A P A G
I| J F C B O F X Q S H M B S T O S X K I C I Q P T G V
J| O D K Z T E M M C X E F Y X L V M D K Q E Y C Z C C
K| Y I Q G Y U D W N L L A O O E E S R U Y F E F I V I
L| C E V P W B Y J I U B H H R C Y Q X G U Z X S Y X H
M| M V H D N Q O L L S X U R S H U C I A T P R W B S D
N| R L Y X J I T N G J U E W D U B B L E D K O V D F T
O| X R Z T B C C T R R C N U N I J H N T O W P G C W Z
P| V N U F M Y I S V B Y V M W Q A F Q C X L U I K Z U
Q| N Y B R F N H G H A J T N B V P P J S Z Y T X J E M
R| W H G K H T U O O Q H Z X M W C O W B A A H U O Y F
S| B C D E D G W F Y V D S E G B L G C H P M K T U O X
T| Z K A C U R V C B K Q Q A L P N J P D G J L K E L R
U| P T T I V S P U K M I M I Y K R V G M J D M Y N D Y
V| Q U L Q C D A B D I Z J C H F H W U P R O Z Q S M O
W| S B N N G W J E Q T S D L U J F R F O L R A J V Q K
X| E J F H K L G A F Y T X P C A I N E X N G I L A H J
Y| A P J A I Z Q V J W F W F V G K U M F S B F O H P P
Z| H O I L R A Z Z P P G O G E T G L Y N K Q J D M K N

The codetable contains 26 randomly sorted alphabets (from up to down). These are used to encrypt the text with an password.

We want to encrypt our sample text with the password "PETER". All we have to do is search the first letter (T) on the left side
of the table. Then you need to search the first letter of the password and search it on the upper side of the table.
Our encrypted first letter is the letter that stands in the cell the two other letters represent. In our case it's: N.
To find the second letter we need to do just the same: Searching the letter of the uncrypted text on the left and the next letter
of the password on the upper side and take the represented letter out of the table. Repeat this till the complete text is encrypted.
The password is always to repeat (PETERPETERPETERPETER) till the text ends.

THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
NEF JROIY XHOGL QOK VVTMC BRLW UHL YPKI OBB

To decrypt the text you just need to do the same as above, just reversed. Search the encrypted letter (N) in the column below the
letter of the password (P) and take the letter on the left of the same row (T). Repeat this and you can encrypt the text easily.



4. Version history
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06.August.2009 - First Release Date (v1.0)


5. Contact
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eMail: loofou@ret-world.de
web: http://sourceforge.net/projects/emucrypttool/