WHAT IS THE THE POLYBIUS SQUARE? WHAT YOU NEED TO KNOW ABOUT THE POLYBIUS SQUARE
THE POLYBIUS SQUARE
The Polybius Square is an method of encryption, used in cryptology, the study of codes solving them. It is a 5 by 5 chart, with a letter in each square. However, there are twenty-six letters in the English alphabet and only twenty-five spots in the square. Traditionally, you would combine two letters into one box, usually I and J. Sometimes, the square is converted to a 6 by 6 square. In this square, there are ten boxes missing were filled with numbers one to ten, in case number are need to be used in the message.
This is a 5 by 5 Polybius Square. Notice that the spot where the letter "I" should be, "J" is also in it. Courtesy of Crypto Corner.
This is a 6 by 6 Polybius Square. Notice the numbers in the bottom two rows. Courtesy of Crypto Corner.
ORIGIN OF THE POLYBIUS SQUARE
The Polybius Square originated in Greece, named after the Greek historian, Polybius. Polybius did not really associate himself with cryptology or encryption of messages. The Greek alphabet consisted of 24 characters, which is enough to fill all but one square which was not used.
A statue of Polybius in Venice, Rome shows a clear depiction of what Polybius may have looked like. Courtesy of Britannica.