From 7bcb52f4fe0513adb154dd3bcf7c359522619655 Mon Sep 17 00:00:00 2001 From: Olga Kunyavskaya Date: Mon, 20 Nov 2023 11:44:53 +0200 Subject: [PATCH] fix formula --- neps/nep-0488.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/neps/nep-0488.md b/neps/nep-0488.md index 0cd8acd7a..101d81689 100644 --- a/neps/nep-0488.md +++ b/neps/nep-0488.md @@ -668,7 +668,7 @@ The rule of encoding is consistent with zkcrypto[^53] and with implementation in #### Compressed points on twisted curve E'(Fp2) -The points on the curve represent by affine coordinates: `(x: Fp2, y: Fp2)`. The elements from $E'(F_{p^2})$ in compressed form are encoded in `[u8; 96]` as *big-endian* encoded $x \in F_{p^2}$. The $y$ coordinate can be detected by the formula: $y = \pm \sqrt{x^3 + 4}$. +The points on the curve represent by affine coordinates: `(x: Fp2, y: Fp2)`. The elements from $E'(F_{p^2})$ in compressed form are encoded in `[u8; 96]` as *big-endian* encoded $x \in F_{p^2}$. The $y$ coordinate can be detected by the formula: $y = \pm \sqrt{x^3 + 4(u + 1)}$. *The highest bit* should be set as 1. This bit indicates that point is encoded in compressed form.