18 lines
586 B
Text
18 lines
586 B
Text
import "ecc/babyjubjubParams.code" as context
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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, field[10] context) -> (field[2]):
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field a = context[0]
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field d = context[1]
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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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