16.5 Elliptic Curve Cryptosystems

• I thought it was very cool to see how we can use elliptic curves and apply the things we've already learned to get cryptosystems.
• All in all, the individual cryptosystems made sense to me but I don't get how they could calculate a point multiplied by an integer so fast on the elliptic curve. I guess it wouldn't take too long if you put the integer in terms of powers of 2 (this way you could do the thing similar to successive squaring but in adding points).