Introduction If you need to send a secret message to a friend, how could you prevent other people from reading it? One way is to encrypt the message—that is, use a secret code that only you and your ...

Gaius Iulius Caesar の名を冠した、もっとも古典的な暗号だ。 ──うむ、これならいける。 Gaius Iulius Caesar、すなわちジュリアス・シーザーは、 共和政ローマの政務官であり、同時に文筆家でもあった。 なるほど。 ではなぜ、彼の名が「暗号」に結びついたのか。

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 ...