How to Securely Store User Passwords with PHP 7's password_hash Function

PHP 7 Password Security Guide: How to Store Passwords Securely with password_hash

In modern web development, protecting user passwords from hacking attempts is crucial. Storing passwords insecurely can lead to easy breaches, resulting in serious security issues. PHP 7’s password_hash function provides developers with a simple yet powerful solution to ensure password security during storage.

This article will guide you on how to use the password_hash function for securely storing passwords, ensuring that passwords are stored as hashed values in the database, thus improving password storage security.

1. Password Hashing Algorithms

Before using the password_hash function, it’s essential to understand password hashing algorithms. Password hashing is a one-way encryption technique that converts plain-text passwords into a non-reversible string. When a user logs in, the system compares the entered password with the stored hash in the database, rather than storing the password in plain text. Even if the database is breached, hackers cannot reverse the hash to recover the original password.

2. Using the password_hash Function

The password_hash function is a built-in function in PHP 7 used to generate password hashes. It requires two parameters: the plain-text password and the hashing algorithm. Below is an example of using the password_hash function to generate a password hash:

$password = "password123";
$hashedPassword = password_hash($password, PASSWORD_DEFAULT);

In the above code, the password string "password123" is set, and then the password_hash function is used to generate the hash, which is stored in the $hashedPassword variable. Using the PASSWORD_DEFAULT constant selects the most secure hashing algorithm available.

3. Verifying the Password

When a user logs in, we need to verify if the entered password is correct. To do this, we can use the password_verify function to compare the entered password with the stored hash from the database. Below is an example of how to verify the password:

$inputPassword = "password123";
if (password_verify($inputPassword, $hashedPassword)) {
    echo "Password is correct";
} else {
    echo "Password is incorrect";
}

In this code, the user’s entered password is stored in the $inputPassword variable. Then, the password_verify function is used to compare it with the stored hash password $hashedPassword. If the passwords match, "Password is correct" will be output; otherwise, "Password is incorrect" will be displayed.

4. Additional Security Tips

Although the password_hash function provides a robust password storage mechanism, here are some additional security measures to further enhance protection:

• Use a suitable hashing algorithm: While PASSWORD_DEFAULT is the default algorithm, you can choose other algorithms based on your needs. When selecting a hashing algorithm, consider the balance between security and performance.
• Update hashing algorithms regularly: Over time, some hashing algorithms may become insecure. It’s important to stay updated with security recommendations and update your chosen hashing algorithm as necessary.
• Implement additional protective measures: Relying only on the password_hash function is not enough to guarantee password security. You should also use SSL encryption, enforce strong password policies, and apply other security best practices.

Conclusion

By using the password_hash function, you can easily implement secure password storage. During user login, the system compares the entered plain-text password with the stored hash value, without needing to store the plain-text password. Additionally, it’s essential to choose a secure hashing algorithm and periodically update it to ensure long-term password security.