1. Form, method POST
2. Password hashing.
3. Basic SQL INSERT, SELECT
4. PDO with prepared statements
To register, draw a shape, after receiving HaShirim password and write it to the database using PDO
To authorize draw a form with email and password, emails requested from the database ID and password meet the password hash, if everything is OK - write in the session ID of the user.
On all pages that need to be protected, check the existence of ID in the session.
As a bonus, you can check the data entered and the error output. But it is optional, you first need to do basic functionality
- Password hashing https://php.net/password_hash
- INSERT using PDO https://phpdelusions.net/pdo_examples/insert
Proverka password https://phpdelusions.net/pdo_examples/password_hash