Polybius square

In cryptography, the Polybius square, also known as the Polybius checkerboard, is a device invented by the Ancient Greeks Cleoxenus and Democleitus, and perfected by the Ancient Greek historian and scholar Polybius, for fractionating plaintext characters so that they can be represented by a smaller set of symbols. In cryptography, the Polybius square, also known as the Polybius checkerboard, is a device invented by the Ancient Greeks Cleoxenus and Democleitus, and perfected by the Ancient Greek historian and scholar Polybius, for fractionating plaintext characters so that they can be represented by a smaller set of symbols. The original square used the Greek alphabet: With the modern Latin alphabet, this is the typical form: