MD5 password cracking principles and websites

In theory, MD5 is almost impossible to crack. Chen Xiaoyun only finds a method that can generate the same MD5 value for different data segments (Shan Feng comment: It seems that different data will not generate the same MD5 value, this refers to the reverse thinking method ). But the password is different, because the average person's password is within 10 characters, some people will ~ All uppercase/lowercase letters and numbers within 11 characters are combined to calculate the MD5 value, and then use this huge dictionary to reverse crack (query) the original password value. This is also an example of a classic space-to-time change.

The address of this website is: http://www.cmd5.com/

Copy an MD5 value to the query box of the website, for example, fc5e038d38a57032085441e7fe7010b0, and click "decrypt.
Generally, forums (mobile networks/discuz/phpBB) and general websites use MD5 to calculate the password and store it. Now, we can use this tool to "Restore" the user password.

Appendix 1 Website introduction text: This site has the world's largest database, and the query speed is fast. Most queries are free of charge.
There are a total of 457,354,352,282 real-time queries, including 11-bit and below-11 digits, 8-bit lower-case letters, 7-bit lower-case letters and numbers, and 6-bit upper-case letters and numbers.
There are a total of 176,149,422,453,689 distributed query records in the background, including 12 digits, 9 lowercase letters, numbers, and 7 arbitrary characters.

Postscript: This article does not allow everyone to crack others' passwords. (In fact, if you have not intruded into others' servers, you cannot even obtain their MD5 values) just let everyone think about whether the Password Storage method needs to be changed, for example, using "User Name + password + custom string" as the original MD5 calculation value, rather than just the password