Password Hash - PHP

Introduction

Password hash is a PHP function that can be used to securely hash passwords. It was introduced in PHP 5.5, and provides a simple way to generate a strong, salted and hashed password hash, which can be stored in a database to verify the user's password upon login.

Usage

The syntax for using password hash is:

password_hash ($password, $algorithm, $options)

where:

• $password: is the plain text password that you want to hash.
• $algorithm: is the hashing algorithm to use. It can be one of the following constants: PASSWORD_DEFAULT, PASSWORD_BCRYPT, PASSWORD_ARGON2I or PASSWORD_ARGON2ID.
• $options: is an array of options for the hashing algorithm. It is optional and depends on the algorithm used.

Here is an example of how to use password hash to create a hash for a password:

// Plain text password
$password = 'mySecretPassword';

// Hash the password with the default algorithm
$hash = password_hash($password, PASSWORD_DEFAULT);

// Store the hash in the database
$sql = "INSERT INTO users (username, password_hash) VALUES ('$username', '$hash')";

Verification

To verify a password hash, you can use the password_verify function, which takes the plain text password and the password hash as inputs and returns a boolean value indicating whether the password is correct.

Here is an example of how to verify a password hash:

// Plain text password
$password = 'mySecretPassword';

// Stored hash in the database
$hash = '$2y$10$XiFZAHLym/teXMN1JcY75eKVX.MHx2vLJgDdcptucnlbv4J4sKM2O';

// Verify the password hash
if (password_verify($password, $hash)) {
    echo 'Password is valid!';
} else {
    echo 'Password is invalid!';
}

Conclusion

Password hash is a simple and secure way of hashing passwords in PHP. It provides a standardized way of generating strong, salted and hashed password hashes, which can be stored in a database and verified upon login. It is recommended to use password hash for all password related tasks in PHP.