Deloitte, one of the biggest accounting and audit firms in the world, has denied falling victim to a targeted attack by the Brain Cipher ransomware gang. Deloitte, one of the so-called Big Four ...

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.