P {Upper} — Uppercase characters.

p {upper}—大写字符。

youdao

Palindromes should be reported all in uppercase characters.

全部用大写字母来输出回文。

youdao

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。

youdao

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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