Md5 is an algorithm created by ross riverst in 1997 for the initial purpose of verifying the integrity of the document and digital signature. You go through the user chart for any of the 10 years old projects, and the rate behind the password field follows a sequence of 32-digit hexadecimal characters -- the md5 encryption principle and the most typical legacy. I've been writing code for over a decade from the php md5 to java's massagedigest. Getinstance, and i'm pretty good at this algorithm, but i have to tell the new guy every time。
What do you mean by md5 encryption
Md5 input is a message of any length, with a fixed output of 128 bit summary, i. E. 32 hexadecimal characters. The whole process is carried out in three steps: the pre-processing phase doubles the message to 64 bytes, adding a multiple of one and zero to 64 by the end, with eight bytes of original message length added at the end; the four 32-bit repository abcds initialize the magic number written in rfc 1321; and each 64-bit group is sent to a compression function, which is internal to 16-step non-linear calculations (sin, xor, or combination variants) in four rounds, adding 2 ^32 plus the value of the abcd。
It's just a sentence: cut the data, throw it in a mixer four-wheel, throw out 128 bits. You changed the bit in the input, the output was completely differentAvalanche effectI don't know. In turn, it wants to take back the original input from 128 abstracts, one-way, extremely difficult, which is why it was trusted that year。
Md5 encryption secure
In 2004, the wang xiaoyun team gave a method of collision tectonics, and the merkle collision attack in 2008 actually hit firefox and thunderbird signature verification. Now that a consumer-grade gpu ran md5 for about a few seconds, the rainbow watch directly turns "violent guess codes" into "checklists."。Use md5 as a password, hashi. It's a nudist security accident in 2026I don't know. If you're writing new items, use the password fieldBcrypt or argon2Sha-256, check the file. Don't be a pussy。
But md5 isn't completely dead. You do a complete check of the downloaded file, or you do a fingerprint for the redis cache. It's fast, it's good enough, and no one's gonna hit a cache. Just remember one line: something about a secure border, don't touch md5。
When they bring new people, they ask the most about "md5 encryption." honestly, the algorithm itself is not complicated, so it can be written by hand one afternoon. What's really hard is you have to figure out its boundaries -- what's reasonable about it, what's mine. The tools are not absolutely good or bad. The wrong place is the problem。
