how blockchain verify private keys, I am sure nodes does not store private key, so how private key is validated?

Question

it's the doubts lie in the very core concept, but I wanna know how the nodes know that the private+public key is right.

Answer 1

Blockchains use elliptic curve cryptography which is a type of public key cryptography.

In a public key cryptosystem the private key is used to sign a message, and the public key is used to verify a message.

Blockchains don't need the private key to verify a transaction.