From 8eb68d3fe050cdba06546e29fc18547c1cee7ae9 Mon Sep 17 00:00:00 2001
From: jude <jude@jellywx.com>
Date: Fri, 21 Apr 2023 20:39:58 +0100
Subject: [PATCH] Add proof of fortification

---
 static/js/modules/crypto/random_primes.js |   5 +-
 static/js/modules/interface/proofs.js     | 125 +++++++++++++++++++++-
 2 files changed, 123 insertions(+), 7 deletions(-)

diff --git a/static/js/modules/crypto/random_primes.js b/static/js/modules/crypto/random_primes.js
index 04ec236..46fe7cf 100644
--- a/static/js/modules/crypto/random_primes.js
+++ b/static/js/modules/crypto/random_primes.js
@@ -1,6 +1,6 @@
 import { mod_exp } from "./math.js";
 
-export const KEY_SIZE = 2048;
+export const KEY_SIZE = 512;
 
 export function cryptoRandom(bits) {
     if (bits === undefined) {
@@ -100,8 +100,7 @@ export function generate_prime() {
 export function generate_safe_prime() {
     while (true) {
         let n = generate_prime();
-        // This does not generate safe primes! But it takes forever to find safe primes of size 1024, so this will do.
-        if (small_prime_test((n - 1n) / 2n) /* && miller_rabin((n - 1n) / 2n, 40) */) {
+        if (small_prime_test((n - 1n) / 2n) && miller_rabin((n - 1n) / 2n, 40)) {
             return n;
         }
     }
diff --git a/static/js/modules/interface/proofs.js b/static/js/modules/interface/proofs.js
index cc79428..21eeb38 100644
--- a/static/js/modules/interface/proofs.js
+++ b/static/js/modules/interface/proofs.js
@@ -1,4 +1,5 @@
 import { cryptoRandom } from "../crypto/random_primes.js";
+import { Region } from "./map.js";
 
 function cryptoRange(upper) {
     // This is ridiculous: why implement a BigInt primitive, have it behave like a number, and then _not_ offer
@@ -294,8 +295,124 @@ export function verifyRange(obj, key) {
 window.verifyRange = verifyRange;
 
 /**
- *  - We prove that the set contains |S| - 2 zeros, with the final pair summing to zero
- *  - We also attach some form of adjacency guarantee: that is, we prove the sums on all adjacent pairs are zero
- *  - We also attach a range proof for the new region values
+ * - We prove that the set contains |S| - 2 zeros, with the final pair summing to zero
+ * - We also attach some form of adjacency guarantee: that is, we prove the sums on all adjacent pairs are zero
+ * - We also attach a range proof for the new region values
  */
-export function proveFortify() {}
+export function proveFortify(fortify) {
+    let proofs = [];
+    let privateInputs = [];
+
+    let regionNames = Object.keys(fortify).sort();
+    for (let x = 0; x < ROUNDS; x++) {
+        let psi = cryptoShuffle(structuredClone(regionNames)).join("");
+        let psiMap = {};
+        for (let i = 0; i < regionNames.length; i++) {
+            psiMap[regionNames[i]] = psi[i];
+        }
+
+        let newRegions = structuredClone(fortify);
+
+        // Rearrange keys
+        for (let r of regionNames) {
+            newRegions[psiMap[r]] = fortify[r].pubKey.encrypt(fortify[r].plainText);
+        }
+
+        let edges = [];
+        let proofEdges = [];
+
+        // Attach edges
+        for (let i = 0; i < regionNames.length; i++) {
+            let region = regionNames[i];
+            let psiRegion = psi[i];
+
+            for (let n of Region.getRegion(region).neighbours) {
+                if (regionNames.includes(n.name)) {
+                    let psiNeighbour = psiMap[n.name];
+
+                    if (psiNeighbour > psiRegion) {
+                        let salt = cryptoRandom(128);
+                        let hasher = new jsSHA("SHA3-256", "TEXT");
+                        hasher.update(psiRegion);
+                        hasher.update(psiNeighbour);
+                        hasher.update(salt.toString(16));
+                        let hash = hasher.getHash("HEX");
+
+                        edges.push({
+                            hash: hash,
+                            salt: salt,
+                            edge: [psiRegion, psiNeighbour],
+                        });
+                        proofEdges.push(hash);
+                    }
+                }
+            }
+        }
+
+        newRegions.edges = cryptoShuffle(proofEdges);
+
+        proofs.push(newRegions);
+        privateInputs.push({
+            psi: psi,
+            edges: edges,
+        });
+    }
+
+    let coins = getCoins(JSON.stringify(proofs));
+    let verifications = [];
+
+    for (let i = 0; i < ROUNDS; i++) {
+        let coin = coins[i];
+        let proof = proofs[i];
+        let input = privateInputs[i];
+
+        if (coin === 1) {
+            // Show |S| - 2 zeroes
+            let verification = {
+                regions: {},
+            };
+            let pairCipherText = null;
+            let pair = [];
+
+            for (let r of regionNames) {
+                if (proof[r].plainText === 0n) {
+                    verification.regions[r] = proof[r].proveNI();
+                } else if (pairCipherText === null) {
+                    pairCipherText = proof[r].clone();
+                    pair.push(r);
+                } else {
+                    pairCipherText.update(proof[r]);
+                    verification.pairCipherText = pairCipherText.proveNI();
+                    pair.push(r);
+                }
+            }
+
+            // Show pair is joined by edge
+            let pairName = pair.sort();
+            console.log(input);
+            verification.pairEdgeSalt = input.edges.find(
+                (e) => e.edge[0] === pairName[0] && e.edge[1] === pairName[1]
+            );
+
+            verifications.push(verification);
+        } else {
+            // Show isomorphism
+            verifications.push({
+                psi: input.psi,
+                salts: input.edges.map((e) => e.salt),
+            });
+        }
+    }
+
+    return {
+        fortify: fortify,
+        proofs: proofs,
+        verifications: verifications,
+    };
+}
+
+window.proveFortify = proveFortify;
+
+function verifyFortify(obj, key) {}
+
+// proveRegions({A:paillier.pubKey.encrypt(0n),B:paillier.pubKey.encrypt(3n),C:paillier.pubKey.encrypt(-3n),D:paillier.pubKey.encrypt(0n),E:paillier.pubKey.encrypt(0n)})