How does using a dynamic salt improve the security of password hashing in PHP?

Using a dynamic salt improves the security of password hashing in PHP by adding an extra layer of randomness to each hashed password. This makes it harder for attackers to use precomputed rainbow tables or dictionary attacks to crack passwords. By generating a unique salt for each password, even if two users have the same password, their hashed values will be different due to the unique salt.

// Generate a dynamic salt
$salt = bin2hex(random_bytes(16));

// Hash the password with the dynamic salt
$hashed_password = password_hash($password . $salt, PASSWORD_DEFAULT);