The German police made the mistake in late 1941 of switching from the rather strong Double Transposition cipher to the more ... We encipher each vertical pair. Find the first letter of each ...
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.
Some results have been hidden because they may be inaccessible to you