General

The crate contains the playfair, the two square and the four square ciphers. Note all are pre computer cipers. Do not feel like protecting data of any value with them. Any of those are crackable in very short time.

Basics on squares

The library offers two square sizes - 5 to 5 and 6 to 6. If using 5 to 5 the encryption is done with the basic setup of the square like this

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

Only characters contained in the square can be encrypted. Which means with the 5 to 5 square there are no digits encryptable.

If the library is used with the 6 to 6 square the basic setup is like this

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 0 1 2 3 
4 5 6 7 8 9

With the 6 to 6 square the characters A-Z and 0-9 are encryptable.

This charactersitics applies to the TwoSquare and the FourSquare cipher aswell. The only differ in the number of squares used.

When using method encrypt the payload is converted to uppercase and any character not within the the square is removed.

So you don't need to clear off not encryptable characters when using this library.

Passkeys

To use the ciphers as they where intended to be used one must seed them with a passkey. Empty passkeys are possible. Not encryptable characters in the passkey are removed again. Note the removement happends stealthy - no error is raised.

Benchmarking

The library can be benchmarked using criterion. Benchmarked are all ciphers - encryption and decryption aswell. For any benchmark a randomly generated string of 20000 characters is used. To benchmark just

cargo bench

Playfair Cipher

Implementation of the PlayFair cipher - nothing special, nothing useful, just for fun.

Encrypt

Example 5 to 5

use playfair_cipher::{playfair::PlayFairKey, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let pfc = PlayFairKey::new_5_to_5("playfair example");
match pfc.encrypt("hide the gold in the tree stump") {
  Ok(crypt) => {
    assert_eq!(crypt, "BMODZBXDNABEKUDMUIXMMOUVIF");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Example 6 to 6

use playfair_cipher::{playfair::PlayFairKey, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let pfc = PlayFairKey::new_6_to_6("play 3645 fair 8760 example");
match pfc.encrypt("hide the gold in the tree stump at 5 o'clock.") {
  Ok(crypt) => {
    assert_eq!(crypt, "SXG0SJGQW5H5OUGX2MXMXQUN733Q0WDPNDHB");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Decrypt

Example 5 to 5

use playfair_cipher::playfair::PlayFairKey as PlayFairKey;
use playfair_cipher::errors::CharNotInKeyError as CharNotInKeyError;
use playfair_cipher::cryptable::Cipher;

let pfc = PlayFairKey::new_5_to_5("playfair example");
match pfc.decrypt("BMODZBXDNABEKUDMUIXMMOUVIF") {
  Ok(crypt) => {
    assert_eq!(crypt, "HIDETHEGOLDINTHETREXESTUMP");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};    

Example 6 to 6

use playfair_cipher::{playfair::PlayFairKey, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let pfc = PlayFairKey::new_6_to_6("play 3645 fair 8760 example");
match pfc.decrypt("SXG0SJGQW5H5OUGX2MXMXQUN733Q0WDPNDHB") {
  Ok(crypt) => {
    assert_eq!(crypt, "HIDETHEGOLDINTHETREXESTUMPAT5OCLOCKX");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Two Square Cipher

Implementation of the TwoSquare cipher - nothing special, nothing useful, just for fun.

Encrypt

Example 5 to 5

use playfair_cipher::{two_square::TwoSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;;

let tsq = TwoSquare::new_5_to_5("EXAMPLE", "KEYWORD");
match tsq.encrypt("joe") {
  Ok(crypt) => {
    assert_eq!(crypt, "NYMT");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Example 6 to 6

use playfair_cipher::{two_square::TwoSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;;

let tsq = TwoSquare::new_6_to_6("EXAMPLE", "KEYWORD");
match tsq.encrypt("Ben Wade takes the 3:10 train to Yuma.") {
  Ok(crypt) => {
    assert_eq!(crypt, "CKNWEBMPEYAPRJLX01WYXJNTKOVLE0");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Decrypt

Example 5 to 5

use playfair_cipher::{two_square::TwoSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let tsq = TwoSquare::new_5_to_5("EXAMPLE", "KEYWORD");
match tsq.decrypt("NYMT") {
  Ok(crypt) => {
    assert_eq!(crypt, "IOEX");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Example 6 to 6

use playfair_cipher::{two_square::TwoSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;;

let tsq = TwoSquare::new_6_to_6("EXAMPLE", "KEYWORD");
match tsq.decrypt("CKNWEBMPEYAPRJLX01WYXJNTKOVLE0") {
  Ok(crypt) => {
    assert_eq!(crypt, "BENWADETAKESTHE310TRAINTOYUMAX");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Four Square Cipher

Implementation of the FourSquare cipher - nothing special, nothing useful, just for fun.

Encrypt

Example 5 to 5

As described at https://en.wikipedia.org/wiki/Four-square_cipher

use playfair_cipher::{four_square::FourSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let fsq = FourSquare::new_5_to_5("EXAMPLE", "KEYWORD");
match fsq.encrypt("joe") {
  Ok(crypt) => {
    assert_eq!(crypt, "DIAZ");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Example 6 to 6

use playfair_cipher::{four_square::FourSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let fsq = FourSquare::new_6_to_6("EXAMPLE", "KEYWORD");
match fsq.encrypt("Ben Wade takes the 3:10 train to Yuma.") {
  Ok(crypt) => {
    assert_eq!(crypt, "PEOQMKXUPDEUSAL201WIADJQI0RJLP");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Decrypt

Example 5 to 5

use playfair_cipher::{four_square::FourSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let fsq = FourSquare::new_5_to_5("EXAMPLE", "KEYWORD");
match fsq.decrypt("DIAZ") {
  Ok(crypt) => {
    assert_eq!(crypt, "IOEX");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

Example 6 to 6

use playfair_cipher::{four_square::FourSquare, errors::CharNotInKeyError};
use playfair_cipher::cryptable::Cipher;

let fsq = FourSquare::new_6_to_6("EXAMPLE", "KEYWORD");
match fsq.decrypt("PEOQMKXUPDEUSAL201WIADJQI0RJLP") {
  Ok(crypt) => {
    assert_eq!(crypt, "BENWADETAKESTHE310TRAINTOYUMAX");
  }
  Err(e) => panic!("CharNotInKeyError {}", e),
};

That's it.