As I know from the Elliptic Curve Diffie Hellman (ECDH), you can create a "Shared Key": https://asecuritysite.com/encryption/ecdh2
This will look like this:
dA × dB × G = Shared Key QB = dB × G QA = dA × G
But is it possible to get the sum of dA and dB? (Plusing the value of each private key?)
dA + dB × G = ???
How to get a "Shared Key" when adding each private key (plus)?