Merge pull request #255 from privacy-scaling-explorations/fix/inv

Add check for F1Field `inv(0n)`
privacy-scaling-explorations · Apr 22, 2024 · 7843c51 · 7843c51
2 parents 39b1a51 + dbc7c70
commit 7843c51
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/packages/utils/src/f1-field.ts b/packages/utils/src/f1-field.ts
@@ -86,6 +86,10 @@ export default class F1Field {
      * @throws if 'a' is zero.
      */
     inv(a: bigint): bigint {
+        if (a === this.zero) {
+            throw new Error("Zero has no inverse")
+        }
+
         let t = this.zero
         let r = this._order
         let newt = this.one

diff --git a/packages/utils/tests/f1-field.test.ts b/packages/utils/tests/f1-field.test.ts
@@ -80,8 +80,10 @@ describe("F1Field", () => {
 
         expect(field.inv(a)).toBe(7n)
         expect(field.inv(b)).toBe(6n)
+    })
 
-        expect(field.inv(0n)).toBe(0n)
+    it("Should throw an error if inv input is 0", () => {
+        expect(() => field.inv(0n)).toThrow("Zero has no inverse")
     })
 
     it("Should lt into the finite field", () => {