Paper claims to prove P != NP

Does it change anything if it's right?

Not really. P != NP is what most computer scientists have long believed to be true because in 40 years no one has found a fast solution to any NP problem. So basically it would just be formal proof of what is already believed to be true.

It would be hard proof that certain encryption algorithms are unbreakable.

Cactuar, I think you have it backwards.


Winning slashdot comment:

We'll know that P != NP if it takes us less time to verify the proof as it took him to generate it.