> If we could get very good and quick algorithm without being it slow, we would use it. No, that's simply not true, and that's what the person you replied to w

> If we could get very good and quick algorithm without being it slow, we would use it. No, that's simply not true, and that's what the person you replied to was trying to say. For a password hashing algorithm, you actively want it to be slow - to have a mathematically guaranteed minimum amount of time that each attempt takes, regardless of implementation. This is a security property of a password-hashing algorithm. It is a necessary attribute - you can't have a "good" password-hashing algorithm whose output can be computed arbitrarily quickly. What you might be saying is that if an inefficient implementation is slow, we'd like to speed it up. Sure. The requirement of a good algorithm is that the most efficient implementation possible is slow.