‣ In classical cryptography, the Bifid Cipher, is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion. It was invented around 1901 by Felix Delastelle
ENCRYPTION:
First, an alphabetic polybius square is drawn up, where the I and the J share the same position:
1 | 2 | 3 | 4 | 5
1 A B C D E
2 F G H I/J K
3 L M N O P
4 Q R S T U
5 V W X Y Z
So if your word is 'Pretty' then it would be:
P - 35
R - 42
E - 15
T - 44
T - 44
Y - 54
Ngayon nakuha na natin ang katumbas ng bawat letra, ang gagawin naman natin ay ihihiga ito;
P R E T T Y
3 4 1 4 4 5
5 2 5 4 4 4
Ayan, susunod ay kukunin natin yung mga numero galing kanan pakaliwa, gaya nito:
3 4 1 4 4 5 5 2 5 4 4 4
Then divided up into pairs again:
34 14 45 52 54 44
Then using the square above, the pairs will be converted back to letters again and it will be:
34 14 45 52 54 44
O D U W Y T
PRETTY = ODUWYT
In this way, each cipher text character depends on two plaintext characters, so the bifid is a diagraphic cipher, like the Playfair cipher. To decrypt, the procedure is simply reversed.
YOU ARE READING
DECIPHER: A Compilation of codes and ciphers
Random✘ - - - DECIPHER is a book compilation that tackles different, new and old codes/ciphers. In addition, this book begins with the definition of cryptography along with it's different terminology for begginers, and better understanding. Interested? W...
