我碰到这个code：

字节的Vigenere密码，以解密误差

但试图遵循的规则我做了一个新问题了。

But trying to follow the rules I made a new question about it.

下面的算法使用，我设法得到一个更好的理解到它：

The following algorithm is used and I'm trying to get a better understanding into it:

Byte[] result= new Byte[plaintext.Length];

key = key.Trim().ToUpper();

int keyIndex = 0;
int keylength = key.Length;

for (int i = 0; i < plaintext.Length; i++)
{
    keyIndex = keyIndex % keylength;
    int shift = (int)key[keyIndex] - 65;
    result[i] = (byte)(((int)plaintext[i] + shift) % 256);
    keyIndex++;
}

我是正确的思维的关键需要进行修整，因为它是在统一code？因此，从资本中减去65产生一个共同的字符/符号？

Am I right in thinking the key needs to be trimmed as it is in Unicode? therefore subtracting 65 from a capital produces a common character/symbol?

推荐答案

为大写字母A的ASCII值是65. 键的所有字符被转换为大写，这仅返回每个字母的英文字母指数键。

The ASCII value for the capital A is 65. All characters in key are converted to uppercase, this would simply return the alphabetical index of each letter in key.

在键，每个字母被转换为数字的方式，并在原字符串中的每个字母是移字母这个数字职务。

Each letter in key is converted to a number that way, and each letter in the original string is "shifted up the alphabet" that number of positions.

如果你的关键是坏，这会变成数字1,0和3，然后应用到的Hello World，如下所示：

If your key was BAD, this would turn into the numbers 1, 0 and 3, then applied to "hello world" as follows:

Hello world
10310310310 <-- added to each character
Ieomo#xoumd

您可以通过添加下面这属于你的code证明这一点：

You can demonstrate this by adding this code below yours:

StringBuilder demonstration = new StringBuilder();
foreach (byte b in result)
{
    demonstration.Append((char)b);
}
Console.WriteLine(demonstration.ToString());