Introduction to ciphers and substitution. Alice and Bob and Carl and Julius: terminology and Caesar Cipher ; The key to the matter: generalizing the Caesar Cipher ; Multiplicative ciphers ; Affine ...

Cryptography is nearly as old as human language. Many civilizations felt the need to conceal their messages using more or less sophisticated encryption methods, as demonstrated by some documentary ...

Abu Yusuf Yaqub ibn Ishaq as-Sabbah al-Kindi was a man of many disciplines, born in Kufa, Iraq around 801 AD. He was raised in Basra and educated in Baghdad. There his scholarship brought him to the ...