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如何确保加密长度与给定的字符串相同

[英]How to ensure the encrypted length are same as the given string

原文 2015-08-11 10:28:49 5 2 java/ encryption

Hi is it possible to encrypt the string with the certain length that i want? 嗨，有可能用我想要的一定长度来加密字符串吗？ for example: i want to encrypt this string BI000001 to something like hex value A3D5F2ARD3 (random) fixed it at 10 length. 例如：我想将此字符串BI000001加密为十六进制值A3D5F2ARD3 （随机），将其长度固定为10。 Therefore when user enter this value A3D5F2ARD3 , system will based on this value and decrypt it to get back the value BI000001 . 因此，当用户输入该值A3D5F2ARD3 ，系统将基于该值并将其解密以获取值BI000001 。

is it possible to do this in java? 有可能在Java中做到这一点吗？

I tried a lot of method but all encrypted length are way too long. 我尝试了很多方法，但是所有加密长度都太长。

2 个解决方案

I am not aware of any JDK built-in Java encryption method which provides this feature. 我不知道任何提供此功能的JDK内置Java加密方法。 Then again, I am not an encryption expert, but I guess such a custom feature won't be built in the JDK. 再说一次，我不是加密专家，但是我想JDK不会内置这种自定义功能。 Maybe this discussion is also useful: https://crypto.stackexchange.com/questions/6098/is-there-a-length-preserving-encryption-scheme 也许此讨论也很有用： https : //crypto.stackexchange.com/questions/6098/is-there-a-length-preserving-encryption-scheme

Why do you want to preserve size of the string? 为什么要保留字符串的大小？ maybe there is another solution for your problem. 也许您的问题还有另一种解决方案。

Typically you would use a block cipher such as AES to encrypt data. 通常，您将使用诸如AES之类的分组密码来加密数据。 Block ciphers (as their name suggest) work in blocks of data of a fixed size, for example AES works in blocks of 128 bits. 分组密码（顾名思义）以固定大小的数据块工作，例如AES以128位的块工作。 If a block cipher encounters input smaller than the block size it pads it , which is likely why you are seeing the ciphertext larger than the plaintext. 如果分组密码遇到小于分组大小的输入，它将填充它，这很可能就是您看到的密文大于明文的原因。