The blinding factor used for notification transactions incorporates and outpoint being spent by the notification transaction.
This ensures that blinding factors will always be unique, even if a user sends a notification transaction to the same recipient multiple times while spending funds from the same address.
Since some common EC libraries have ECDH functions that only return the x value of the resulting point, only use the x value for calculating scalar shared secrets.
The blinding factor used for notification transactions incorporates and outpoint being spent by the notification transaction.
This ensures that blinding factors will always be unique, even if a user sends a notification transaction to the same recipient multiple times while spending funds from the same address.
Since some common EC libraries have ECDH functions that only return the x value of the resulting point, only use the x value for calculating scalar shared secrets.