3 ms·
It's funny. A few years ago I gave a short talk/lesson at my workplace on the mathematics behind ECDSA and coded a visualization of the procedure very similar t
by fluoridation 3y ago
It's funny. A few years ago I gave a short talk/lesson at my workplace on the mathematics behind ECDSA and coded a visualization of the procedure very similar to this. An interesting fact about the finite field curve is that, because the plane loops around on both axes, given an addition A + B = C, there's many straight lines that pass through A, B, and -C. When animating the line to find the sum, I had to optimize the path taken to not fill the screen with lines, because the most straightforward line has a slope comparable to the height of the screen (i.e. it's nearly vertical), so rendering it is almost equivalent to a rectangle fill.
- syncsynchalt 3y agoThere’s an interesting (to me) implementation detail in the A+B=-C lines on this page. It's possible to show the true lines with the toy curve, but the X25519 animation at the top of the page is a cheat: it uses the correct slope IIRC, draws the dot following that slope for five wraparounds, but then cheats and jumps to the needed height and does only the last line to its destination. If I'd done the actual number of wraparounds used in a typical X25519 point addition it'd be like TV snow, or would take hours!