discuz! x2.5 discuz security question algorithm

Today, a friend asked me if the answer to a discuz security question could be forgiven. Or crack it. I paid attention to a password before, but I only remembered it was very short. I thought it was MD5 taken from substr. Finally, after looking at the source code for a long time, it was indeed MD5 encrypted. However, the encryption process was a bit confusing
No security question
Mother's name
Grandpa's name
City where father was born
Name of one of your teachers
The model number of your personal computer
The name of your favorite restaurant
Driver’s license The last four digits
The encryption process is to encrypt the value first. For example, my question is "the last four digits of the driver's license" and the value of value is 7. The MD5 of 7 is 8f14e45fceea167a5a36dedd4bea2543. My answer is "1v1.name", here put the MD5 values ​​​​of 1v1.name and 7 together, that is, "1v1.name8f14e45fceea167a5a36dedd4bea2543" The encrypted MD5 value is "f5d8e00a4ebc9ead4611c04706ae05fd" and then take the 8-digit password from 17th to 24th "4611c047" "4611c047 is the password in the database
Demo
7
8f14e45fceea167a5a36dedd4bea2543
1v1.name8f14e45fceea167a5a36dedd4bea2543
f5d8e00a4ebc9ead4611c04706 ae05fd
4611c047

The above introduces the discuz! x2.5 discuz security question algorithm, including the content of discuz!