From 33c018ac83b19d65f7cf77e7d0d83e7ac430f591 Mon Sep 17 00:00:00 2001
From: Florian <florian@technotro.com>
Date: Tue, 2 May 2023 17:41:52 +0200
Subject: [PATCH 1/5] bump bindings

---
 src/bindings | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/bindings b/src/bindings
index 7a8392f59c..0b59f9e3f9 160000
--- a/src/bindings
+++ b/src/bindings
@@ -1 +1 @@
-Subproject commit 7a8392f59c73effffcc484f93ebf117f8b66e21d
+Subproject commit 0b59f9e3f983ca59f5f5f6e62b78fb7d0e25b90f

From a673ceeea546e2b0894e89b9082e25909356c386 Mon Sep 17 00:00:00 2001
From: Florian <florian@technotro.com>
Date: Tue, 2 May 2023 17:42:10 +0200
Subject: [PATCH 2/5] base off of bindings-2

---
 src/lib/hash.ts | 37 +++++++++++++++++++++++++++++++++++--
 src/snarky.d.ts |  7 +++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/lib/hash.ts b/src/lib/hash.ts
index cef036df3d..053b364f9c 100644
--- a/src/lib/hash.ts
+++ b/src/lib/hash.ts
@@ -1,5 +1,10 @@
-import { HashInput, ProvableExtended, Struct } from './circuit_value.js';
-import { Poseidon as Poseidon_, Field } from '../snarky.js';
+import {
+  HashInput,
+  provable,
+  ProvableExtended,
+  Struct,
+} from './circuit_value.js';
+import { Poseidon as Poseidon_, Field, Bool, Circuit } from '../snarky.js';
 import { inCheckedComputation } from './proof_system.js';
 import { createHashHelpers } from './hash-generic.js';
 
@@ -43,6 +48,34 @@ const Poseidon = {
     return Poseidon_.hash(input, isChecked);
   },
 
+  hashToGroup(input: Field[]) {
+    let isChecked = !input.every((x) => x.isConstant());
+    // y = sqrt(y^2)
+    let { x, y } = Poseidon_.hashToGroup(input, isChecked);
+
+    let { x0, x1 } = Circuit.witness(provable({ x0: Field, x1: Field }), () => {
+      // the even root of y^2 will become x0, so the APIs are uniform
+      let isEven = y.toBigInt() % 2n === 0n;
+
+      // r is the second root of sqrt(y^2)
+      let r = y.mul(-1);
+      // we just change the order so the even root is x0 and the odd x1
+      return isEven ? { x0: y, x1: r } : { x0: r, x1: y };
+    });
+
+    // we check that either x0 or x1 match the original root y
+    y.equals(x0).or(y.equals(x1)).assertTrue();
+
+    // and then we check that either x0 or x1 is the expected second root of y^2
+    let y_ = y.mul(-1);
+    y_.equals(x0).or(y_.equals(x1)).assertTrue();
+
+    return {
+      x,
+      y: { x0, x1 },
+    };
+  },
+
   update(state: [Field, Field, Field], input: Field[]) {
     let isChecked = !(
       state.every((x) => x.isConstant()) && input.every((x) => x.isConstant())
diff --git a/src/snarky.d.ts b/src/snarky.d.ts
index b9fcd7c58f..a23c38ae7f 100644
--- a/src/snarky.d.ts
+++ b/src/snarky.d.ts
@@ -1101,6 +1101,13 @@ declare const Poseidon: {
     input: Field[],
     isChecked: boolean
   ): [Field, Field, Field];
+  hashToGroup(
+    input: Field[],
+    isChecked: boolean
+  ): {
+    x: Field;
+    y: Field;
+  };
   prefixes: Record<
     | 'event'
     | 'events'

From 167de551ca75ac29e7bdfdf466657f2314db6617 Mon Sep 17 00:00:00 2001
From: Florian <florian@technotro.com>
Date: Wed, 3 May 2023 13:38:47 +0200
Subject: [PATCH 3/5] bump bindings

---
 src/bindings | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/bindings b/src/bindings
index 0b59f9e3f9..d86ea91c54 160000
--- a/src/bindings
+++ b/src/bindings
@@ -1 +1 @@
-Subproject commit 0b59f9e3f983ca59f5f5f6e62b78fb7d0e25b90f
+Subproject commit d86ea91c54a398a2f562f92586bc56dc3e5cd149

From f557db481d407396816b15f466b1fa126ded4127 Mon Sep 17 00:00:00 2001
From: Florian <florian@technotro.com>
Date: Wed, 3 May 2023 15:00:26 +0200
Subject: [PATCH 4/5] bindings

---
 src/bindings | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/bindings b/src/bindings
index d86ea91c54..89e2d3c295 160000
--- a/src/bindings
+++ b/src/bindings
@@ -1 +1 @@
-Subproject commit d86ea91c54a398a2f562f92586bc56dc3e5cd149
+Subproject commit 89e2d3c295bb35dfe7bea6a318686c05c8023897

From 5abe1945257ef0fb0122104397b7733c52312658 Mon Sep 17 00:00:00 2001
From: Florian <florian@technotro.com>
Date: Thu, 4 May 2023 07:34:30 +0200
Subject: [PATCH 5/5] reduce constraints

---
 src/lib/hash.ts | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/src/lib/hash.ts b/src/lib/hash.ts
index 053b364f9c..d4ba94caa1 100644
--- a/src/lib/hash.ts
+++ b/src/lib/hash.ts
@@ -53,27 +53,21 @@ const Poseidon = {
     // y = sqrt(y^2)
     let { x, y } = Poseidon_.hashToGroup(input, isChecked);
 
-    let { x0, x1 } = Circuit.witness(provable({ x0: Field, x1: Field }), () => {
+    let x0 = Circuit.witness(Field, () => {
       // the even root of y^2 will become x0, so the APIs are uniform
       let isEven = y.toBigInt() % 2n === 0n;
 
-      // r is the second root of sqrt(y^2)
-      let r = y.mul(-1);
-      // we just change the order so the even root is x0 and the odd x1
-      return isEven ? { x0: y, x1: r } : { x0: r, x1: y };
+      // we just change the order so the even root is x0
+      // y.mul(-1); is the second root of sqrt(y^2)
+      return isEven ? y : y.mul(-1);
     });
 
+    let x1 = x0.mul(-1);
+
     // we check that either x0 or x1 match the original root y
     y.equals(x0).or(y.equals(x1)).assertTrue();
 
-    // and then we check that either x0 or x1 is the expected second root of y^2
-    let y_ = y.mul(-1);
-    y_.equals(x0).or(y_.equals(x1)).assertTrue();
-
-    return {
-      x,
-      y: { x0, x1 },
-    };
+    return { x, y: { x0, x1 } };
   },
 
   update(state: [Field, Field, Field], input: Field[]) {