In Listing 2, notice the many sets of lowercase and uppercase characters.

要注意清单2中很多成对的小写和大写字符。

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These markers could have any name and may not be in all uppercase characters.

这些标志可以是任何名称，可以不是全大写的。

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The test links to two functions that print the message again: the first time in all uppercase characters and then again in lowercase characters.

该测试程序链接到再次打印该消息的两个函数上：第一次都用大写字符，第二次都用小写字符。

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You can brute force it and unfortunately, the so-called Caesar cipher is not very secure because if you assume, for our purposes in English alphabet with 26 characters, say all lowercase for all uppercase, my God, you only have to try like 24, 25, 26 possible rotations until you can figure out what his secret message is.

你可以强行解密但是不幸地是，所谓的凯撒密码不是很安全的,因为如果假设，对于我们的26个字符的字母表,指明所有的小写为大写，我的天，你只要试24，25次，26次就可以解答出,密文的内容。

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The book rightly recommends forcing users to mix uppercase and lowercase characters, digits and punctuation characters to create more secure passwords.

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From there, I can change my password and they recommend that I have 8-20 characters, with a mix of uppercase and lowercase letters, numbers and special characters.

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You'll need a password of 7 to 12 characters, one uppercase, one lowercase, one number and, preferably, one character like an exclamation point or ampersand.

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