How secure is this hash? (Php)

Question

function oneWayEncrypt($string) { 
    $salt = md5($string."yHuJ@8&6%4#%([@d-]"); 
    $salt2 = md5($string."@!#&+-)jU@[yT$@%"); 

    $string = hash('sha512',"$salt$string$salt2"); 

    return $string; 
} 

Answer 1

Using SHA-512 is a good idea to get a cryptographically strong hash, but your choice of salt does not add extra protection. In particular, salt is only good if its value is random and cannot be predicted in advance. This allows an attacker to pre-compute a table of known hashes with which you can try to attack your database. If the salt is known, then the attacker can simply precompute the hash value table with a solid salt relationship.

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Answer 2

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Answer 3

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In addition, use a random and unique salt for each hash operation and store it with the hash so that you can play back the hash for comparison.