Elliptic Curve Arithmetic

in

Now, if you’ve ever tried to do math on an elliptical surface (which is not recommended), you might have noticed it gets pretty complicated. But don’t freak out! We’re here to simplify things for you with our handy-dandy tutorial.

First off, let’s start with the basics. An elliptic curve is essentially a fancy way of drawing a bunch of points on a curvy line and calling them “special.” These special points have some pretty cool properties that make them useful in cryptography namely, they can be used to encrypt and decrypt data.

Now, how we do arithmetic on these elliptic curves. It might sound like a daunting task at first, but trust us when we say it’s not as bad as it seems. In fact, it’s kind of fun!

To begin with you need to choose your curve. This is where the math gets a little bit tricky, so bear with us here. You want to pick an elliptic curve that has some nice properties for cryptography purposes (like being difficult to factor or having large prime factors). There are plenty of resources out there to help you do this just Google “elliptic curves for cryptography” and you’ll find all sorts of helpful information.

Once you’ve chosen your curve, it’s time to start doing some math! Let’s say we have two points on our elliptic curve: P1 = (x1, y1) and P2 = (x2, y2). To add these two points together, we follow a simple algorithm.

First, find the difference between their x-coordinates: delta_x = x2 x1. If this value is zero, you’ve got yourself a special point called “the identity” and your answer is just P1 (since adding anything to the identity gives you back the same thing).

Next, calculate the slope of the line that connects these two points: m = (-y2 + y1) / delta_x. If this value is undefined or infinity, we’ve got another special point called “the vertical” and our answer is just P1 (since adding anything to a vertical gives you back the same thing).

Now, find the x-coordinate of the third point on our elliptic curve: delta_x2 = m^2 x1 x2. If this value is negative or infinity, we’ve got another special point called “the inflection” and we need to do some extra calculations to get our answer (which we won’t go into here).

Finally, find the y-coordinate of our third point: delta_y = m * (x1 delta_x2) y1. Our new point is P3 = (delta_x2, delta_y), which we can use to encrypt or decrypt data using our chosen elliptic curve.

Now, some of the cool properties that make elliptic curves so useful in cryptography. For starters, they have a nice property called “discrete logarithm” this means that it’s easy to multiply two points together on our elliptic curve (which is what we do when we encrypt data), but it’s much harder to figure out which two points were multiplied together in the first place.

This makes them perfect for use in cryptography, since it means that even if someone intercepts your encrypted message, they won’t be able to decipher it without knowing the secret key (which is essentially a fancy way of saying “the answer to a really hard math problem”). And best of all, elliptic curves can be used in both symmetric and asymmetric encryption schemes which means that they’re incredibly versatile and useful for a wide variety of applications.

Elliptic curve arithmetic: the fun way to do math on curvy lines. It might seem daunting at first, but once you get the hang of it, it’s actually pretty easy (and kind of cool). So give it a try who knows? You might just become an elliptic curve arithmetic expert in no time!

SICORPS