....

static/js/modules/crypto/paillier.js

@@ -5,7 +5,16 @@ const PAILLIER = 0;
 const JURIK = 1;
 
 class Ciphertext {
-    constructor(key, plainText, r) {
+    constructor(key, plainText, r, set) {
+        if (set !== undefined) {
+            this.pubKey = key;
+            this.plainText = plainText;
+
+            this.readOnly = false;
+
+            return;
+        }
+
         if (r === undefined) {
             // Use the optimised form using Jacobi classes
             r = cryptoRandom();
@@ -107,6 +116,15 @@ class Ciphertext {
     asReadOnlyCiphertext() {
         return new ReadOnlyCiphertext(this.pubKey, this.cipherText);
     }
+
+    clone() {
+        let c = new Ciphertext(this.pubKey, this.plainText, 0, true);
+        c.cipherText = this.cipherText;
+        c.r = this.r;
+        c.mode = this.mode;
+
+        return c;
+    }
 }
 
 class ValueProofSessionProver {