Getting the hash of a string?

Question

PHP

I need to get a hash for strings that users will enter.
The hashes of different strings should never match. Question: is md5
suitable for my purposes , given that the length of the string can be up to 400 characters? Or are there better solutions?

Answer 1

is md5 suitable for my purposes

No. MD5 does not guarantee the absence of collisions. Their probability is small, but still there.

Answer 2

I don't think there are algorithms for which there are no vulnerabilities. They probably just haven't been found yet.
You can try https://ru.wikipedia.org/wiki/RIPEMD-320. It is in php and, as Wikipedia says, no vulnerabilities have been found in it yet.