[addingnumbers]

Why would you use the same keypair for multiple sites?

[ikiris]

What's stopping an idiot from doing so?

[addingnumbers]

The fact that it's a bare-bones technical demonstration and an idiot would have no wherewithal or purpose to implement it.

[md_]

But then what's it actually demonstrating? That public key cryptography can be used to...validate that someone has a private key?

I feel like I knew that already. ;)