Ensure ciphertexts are cloned to avoid mutating actual object.

static/js/modules/crypto/paillier.js

@@ -23,7 +23,6 @@ class Cyphertext {
             this.cyphertext += key.n2;
         }
 
-        console.log(performance.now());
         this.r = r;
         this.pubKey = key;
         this.plainText = plainText;
@@ -32,16 +31,13 @@ class Cyphertext {
     }
 
     update(c) {
-        this.cyphertext = (this.cyphertext * c.cyphertext) % this.pubKey.n ** 2n;
-        this.r = (this.r * c.r) % this.pubKey.n ** 2n;
+        this.cyphertext = (this.cyphertext * c.cyphertext) % this.pubKey.n2;
+        this.r = (this.r * c.r) % this.pubKey.n2;
         this.plainText += c.plainText;
 
         // Force into range
         while (this.cyphertext < 0n) {
-            this.cyphertext += this.pubKey.n ** 2n;
-        }
-        while (this.r < 0n) {
-            this.r += this.pubKey.n ** 2n;
+            this.cyphertext += this.pubKey.n2;
         }
     }
 
@@ -69,11 +65,11 @@ class ProofSessionProver {
     }
 
     get a() {
-        return mod_exp(this.rp, this.cipherText.pubKey.n, this.cipherText.pubKey.n ** 2n);
+        return mod_exp(this.rp, this.cipherText.pubKey.n, this.cipherText.pubKey.n2);
     }
 
     noise() {
-        return mod_exp(this.rp, this.cipherText.pubKey.n, this.cipherText.pubKey.n ** 2n);
+        return mod_exp(this.rp, this.cipherText.pubKey.n, this.cipherText.pubKey.n2);
     }
 
     prove(challenge) {
@@ -102,26 +98,33 @@ export class ReadOnlyCyphertext {
     }
 
     update(c) {
-        this.cyphertext = (this.cyphertext * c.cyphertext) % this.pubKey.n ** 2n;
+        this.cyphertext = (this.cyphertext * c.cyphertext) % this.pubKey.n2;
 
         // Force into range
         while (this.cyphertext < 0n) {
-            this.cyphertext += this.pubKey.n ** 2n;
+            this.cyphertext += this.pubKey.n2;
         }
     }
 
     prove(plainText, a) {
         return new ProofSessionVerifier(this, plainText, a);
     }
+
+    clone() {
+        return new ReadOnlyCyphertext(this.pubKey, this.cyphertext);
+    }
 }
 
 class ProofSessionVerifier {
     constructor(cipherText, plainText, a) {
-        this.cipherText = cipherText;
+        // Clone, otherwise the update below will mutate the original value
+        this.cipherText = cipherText.clone();
         this.cipherText.update(this.cipherText.pubKey.encrypt(-1n * plainText, 1n));
         // Shift the challenge down by 1 to ensure it is smaller than either prime factor.
         this.challenge = cryptoRandom(2048) << 1n;
         this.a = a;
+
+        this.plainText = plainText;
     }
 
     verify(proof) {
@@ -204,3 +207,5 @@ export function generate_keypair() {
 
     return { pubKey, privKey };
 }
+
+// p = a.prove(); v = p.asVerifier(); v.verify(p.prove(v.challenge));