21 lines
622 B
Plaintext
21 lines
622 B
Plaintext
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from "ecc/babyjubjubParams" import BabyJubJubParams;
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// Add two points on a twisted Edwards curve
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// Curve parameters are defined with the last argument
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// https://en.wikipedia.org/wiki/Twisted_Edwards_curve#Addition_on_twisted_Edwards_curves
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def main(field[2] pt1, field[2] pt2, BabyJubJubParams context) -> field[2] {
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field a = context.JUBJUB_A;
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field d = context.JUBJUB_D;
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field u1 = pt1[0];
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field v1 = pt1[1];
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field u2 = pt2[0];
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field v2 = pt2[1];
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field uOut = (u1*v2 + v1*u2) / (1 + d*u1*u2*v1*v2);
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field vOut = (v1*v2 - a*u1*u2) / (1 - d*u1*u2*v1*v2);
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return [uOut, vOut];
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}
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