The Playfair cipher is an incredibLe code system that is both difficult to decrypt without a computer and easily solvable by hand. You might be familiar with the Cryptoquip in the comics section ...

In 1854, Sir Charles Wheatstone invented the cipher known as "Playfair," named for his friend Lyon Playfair, first Baron Playfair of St. Andrews, who popularized and promoted the cipher. Its ...