Shulou(Shulou.com)06/02 Report--

This article introduces what the md5 code refers to, the content is very detailed, interested friends can refer to, I hope it can be helpful to you.

Md5 code is a 128-bit signature obtained after mathematical transformation of the original information according to the open MD5 algorithm, which is irreversible and highly discrete. MD5 code is usually used for encryption and storage of passwords, digital signature, file integrity verification and so on.

Operating environment of this article: Windows7 system, DELL G3 computer

What does md5 code mean?

MD in MD5 stands for Message Digest, which means information summary, but this information summary is not an abbreviation of information content, but a 128bit (bit) signature obtained by mathematically transforming the original information according to the open MD5 algorithm.

This signature has the following characteristics, first of all, it is irreversible, for example, I have a secret text such as: "My Secret Words", after algorithm transformation to get MD5 code (b9944e9367d2e40dd1f0c4040d4daaf7), tell others that according to this MD5 code, there is no systematic way to know what your original text is.

Second, the code is highly discrete, that is, a small change in the original information can lead to a huge change in MD5, such as "ABC" MD5 (902fbdd2b1df0c4f70b4a5d23525e932) and "ABC" (one space) MD5 (12c774468f981a9487c30773d8093561) is very different, and there is no relationship, that is to say, the resulting MD5 code is unpredictable.

Finally, because the code is 128 bits long, the possibility of having the same MD5 code between any information is very low and is generally considered impossible.

Therefore, it is generally believed that MD5 code can uniquely represent the characteristics of the original information, which is usually used for encrypted storage of passwords, digital signature, file integrity verification and so on.

MD5 information summary algorithm:

MD5 message digest algorithm (English: MD5 Message-Digest Algorithm), a widely used cryptographic hash function, can produce a 128bit (16-byte) hash value (hash value) to ensure complete and consistent transmission of information. MD5 was designed by American cryptographer Ronald Linn Rivest and made public in 1992 to replace the MD4 algorithm. The program of this algorithm is regulated in the RFC 1321 standard. After 1996, the algorithm has been proved to have weaknesses and can be cracked. For data that requires a high degree of security, experts generally recommend using other algorithms, such as SHA-2. In 2004, it was proved that MD5 algorithm can not prevent collision (collision), so it is not suitable for security authentication, such as SSL public key authentication or digital signature.

About MD5 code refers to what is shared here, I hope the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.