是否可以从 MD5 和 Java 恢复消息？
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Is it possible to recover message from MD5 and Java?
提问by Prasad
I have the following code.
我有以下代码。
String plaintext = "HelloWorld";
MessageDigest m = MessageDigest.getInstance("MD5");
m.reset();
m.update(plaintext.getBytes());
byte[] digest = m.digest();
BigInteger bigInt = new BigInteger(1,digest);
String hashtext = bigInt.toString(16);
// Now we need to zero pad it if you actually want the full 32 chars.
while(hashtext.length() < 32 ){
hashtext = "0"+hashtext;
}
Now I want to convert it back to the original string. Is it possible?
现在我想将它转换回原始字符串。是否可以？
回答by Andreas Fester
I have tried this. Now I want to convert it back to Original string.
我试过这个。现在我想将它转换回原始字符串。
This is not possible with MD5. It is a one-way hash function.
这对于 MD5 是不可能的。它是一种单向哈希函数。
In order to be able to encrypt and decrypt, you need to use an encryption/decryption algorithm like AES.
为了能够加密和解密，您需要使用像AES这样的加密/解密算法。
See Java? Cryptography Architecture (JCA) Reference Guidefor more information.
看到Java了吗？密码体系结构 (JCA) 参考指南了解更多信息。
