<i>"The encryption password is "Salted" and based on SHA-512, to avoid brute-force attacks. It takes a lot of technical means to find the word password clearly"</i><p>"clearly?" OVH is wrong. Based on this information alone, it is not sufficient to say how costly it is to recover the password. SHA-512 needs to be <i>iterated</i> to make it costly to brute force.<p>For example, a raw SHA-512 hash, even salted, is not iterated and is easy to brute force.
But multiple passes, as in crypt-SHA-512, are iterated and very costly to brute force.