Passkey pop up everywhere, Mike Pound explains what they are! Check out Brilliant's courses and start for free at https://brilliant.org/computerphile/ (episo...
Basically, in public key cryptography, you can generate a set of two big numbers that are mathematically related, one called the private key and one called the public key, collectively called a key pair.
Through a lot of fancy math, you, with your private key, can take a number I give you and give me back another number called a signature. I, with your public key, can do even more fancy math to prove that you do, in fact, have the corresponding private key to the public key I have, based on this signature.
If you give me the wrong signature, I can’t trust that you have the private key, and you don’t get authenticated, but if you give me the right signature, I can trust that you’re you, and you get authenticated.
And what is a private key? How exactly do you “keep” it across multiple devices? It’s all still black magic to me.
Basically, in public key cryptography, you can generate a set of two big numbers that are mathematically related, one called the private key and one called the public key, collectively called a key pair.
Through a lot of fancy math, you, with your private key, can take a number I give you and give me back another number called a signature. I, with your public key, can do even more fancy math to prove that you do, in fact, have the corresponding private key to the public key I have, based on this signature.
If you give me the wrong signature, I can’t trust that you have the private key, and you don’t get authenticated, but if you give me the right signature, I can trust that you’re you, and you get authenticated.