Static Salt vs Random Salt - Security PHP

Question

Is there any working difference between

$hash=sha1($key.$staticSalt);  

and

$hash=sha1($key.$randomSalt);  

Answer 1

A salt is be random by definition; there is no such thing as a 'static salt'. If it is not random, it's not a salt but a key.

The point of the salt is to make sure the attacker has to mount a separate attack for each password he/she wants to crack. In other words, the point of salting a hash is to prevent precomputation attacks (rainbow tables).

The easy solution for getting it right is to use a standard library instead of cutting corners