在这里看看:
古典加密技术(本文介绍了您要使用的4种方法:Caesar，Playfair，Vigerene和希尔) [^ ]
仿射密码C# [一次性填充密码 [

Hi,

Have a look here:
Classical Encryption Techniques (4 of the methods you want to use are explained in this article: Caesar, Playfair, Vigerene and Hill)[^]
Affine cipher C#[^]
One-time pad cipher[^]