Portanto, a questão está praticamente no título ^^.

Abaixo está um pequeno código php que fiz para testar o desempenho no meu servidor (+ captura de tela do resultado) e também mostrar como pretendo usar muito simplesmente password_hash () e password_verify ().

Eu acho que vou com PASSWORD_BCRYPT e custar = 11 o que você acha?

<?php
$startpage = microtime(true);
$userPassword = "ILike5InchesIceCubes";
echo "<h2>Password we work on :    " . $userPassword . "</h2></br></br>";


echo "<b>password_hash($userPassword, PASSWORD_BCRYPT) :</br></b>";
$start1 = microtime(true);
$hash = password_hash($userPassword, PASSWORD_BCRYPT);
echo "Hash is : " . $hash . "</br>";
echo "Encryption took : ". (microtime(true) - $start1) . " seconds </br>";
$start2 = microtime(true);
password_verify($userPassword, $hash);
echo "Password verification took : ". (microtime(true) - $start2) ." seconds </br></br>";

echo "<b>password_hash($userPassword, PASSWORD_DEFAULT) :</br></b>";
$start1 = microtime(true);
$hash = password_hash($userPassword, PASSWORD_DEFAULT);
echo "Hash is : " . $hash . "</br>";
echo "Encryption took : ". (microtime(true) - $start1) . " seconds </br>";
$start2 = microtime(true);
password_verify($userPassword, $hash);
echo "Password verification took : ". (microtime(true) - $start2) ." seconds </br></br>";

$cost = 4;
do {

        echo "<b>password_hash($userPassword, PASSWORD_BCRYPT, [\"cost\" =>" . $cost . "])</br></b>";
    $start1 = microtime(true);
    $hash = password_hash($userPassword, PASSWORD_BCRYPT, ["cost" => $cost]);
        echo "Hash is : " . $hash . "</br>";
        echo "Encryption took : ". (microtime(true) - $start1) ." seconds </br>";
        $start2 = microtime(true);
        password_verify($userPassword, $hash);
        echo "Password verification took : ". (microtime(true) - $start2) ." seconds </br></br>";

        $cost++;

} while ($cost <= 16);
$endpage = microtime(true);

echo "The whole page took : ". ($endpage - $startpage) . " seconds </br>";
?>