is an ancient tool for modern-day public-key cryptography. The privkey is supposedly a skill to write your unique signature. Kinda making it hard to forge your signature. Proof-of-work of sort. You use your signature to sign essentially life-binding contracts and many other important things. How severe is signature fraud?[citation needed] Oh my...
But it is not the point. When cryptography revolution (as they call it) came - they offered encryption and signing. The hype was that it will change everything and blah-blah-blah and we can see that it pretty much hit the adoption ceiling as we speak.
Now blockchain technology offers another clever use of privkey usage - timestamping and money usage. The money usage side if obviously in the spotlight since it is kind to everyone's heat. Unike trying to explainin privacy concept to an average fellow when you probably quickly stall to technical mumbo-jumbo loosing his understanding and any hopes to success.
It is easy with Bitcoin - "if you can keep a secret passphrase secret you can use money that are unforgable, indillutable and unseizable. The downside is floating value."
And yeah, signing and encrypting come as freebies... and timestamping... whatever that is
