How to add the very first key to your Tesla model 3 or model Y?

The question of whether the key card is NFC (Near Field Communications) or RFID (Radio Frequency ID) has been batted around the Tesla forums for the long time.
NFC is an extension of RFID. They use the same concepts and powering mechanisms, and the frequency that NFC uses is the same as one of the standard RFID frequencies.If it had been NFC, perhaps it could have been cloned. That would have allowed you to use your phone as a key without Tesla App.
When it comes to access control, there are two related but distinct concepts: identification and authentication.
Identification simply means knowing who/what you are interacting with. With NFC, the 7-byte unique identifier is often used for identification purposes since it is defined to be unique.
Authentication is an additional step where you cryptographically verify the identity of the token in a way that only the original token could satisfy.Authentication appears to use Elliptic-curve Diffie–Hellman (ECDH). The mechanism appears in theory to be secure.
Each card has four(!) ECDH keys. The vehicle only uses the first ECDH key on the card. I have no idea what the other three might be used for.
Each vehicle has its own ECDH key which it sends to the card to authenticate, along with a 128-bit random challenge. The card responds with a 128-bit response to complete the authentication.
Each card has its own X.509 certificate, which the vehicle does not fetch (even at pairing).

There is an alternative that’s named GaussKeyCard, an open-source Java Card applet that allows you to use a supported Java Card to unlock and start vehicles in the same way that you would with an official Tesla Key Card.

So, you’re able to use a few key-cards, your mobile phone with Tesla App as a key or a special key fob.

Every key that you already have it’s master key that could be used to connect another one to the car.

And the big problem is if you have no one key to unlock and start the car. I had the same problem and after a lot of nights without sleep I’ve figured it out.

I’ve made an device that allows you in a 20 minutes to connect a new key for your car with no keys at all.

The only one that you need is the Teskeywizard, this is the name of my device. If you work with a cars from Vehicle Auctions you should have the same problem time by time.