Elliptic Curve Diffie Hellman

A short video I put together that describes the basics of the Elliptic Curve Diffie-Hellman protocol for key exchanges. There is an error at around 5:30 where I state that the point at infinity is the result of point-doubling a point whose X coordinate is zero. This is incorrect, it should be when the Y coordinate is zero. Also I state 'geographically' instead of 'geometrically'.