《网络安全：公众世界中的秘密通信》Chalie Kaufman <Network Security, Private Communication in a Public World> 中2.1.3节小例子

密文：Cf lqr'xs xsnyctm n eqxxqgsy iqul qf wdcp eqqh,erl lqrx qgt iqul!

明文：If you're reading a borrowed copy of this book,buy your own copy!