Sync with egk-ec

README.md

@@ -1,10 +1,10 @@
 [![License](https://img.shields.io/github/license/JohnLCaron/egk-ec)](https://github.com/JohnLCaron/egk-ec-mixnet/blob/main/LICENSE.txt)
 ![GitHub branch checks state](https://img.shields.io/github/actions/workflow/status/JohnLCaron/egk-ec-mixnet/unit-tests.yml)
-![Coverage](https://img.shields.io/badge/coverage-89.3%25%20LOC%20(1424/1595)-blue)
+![Coverage](https://img.shields.io/badge/coverage-89.5%25%20LOC%20(1470/1642)-blue)
 
 # Egk Elliptic Curves Mixnet 
 
-_last update 04/28/2024_
+_last update 05/05/2024_
 
 Implementation of a mixnet using the [ElectionGuard Kotlin Elliptical Curve library](https://github.com/JohnLCaron/egk-ec),
 and the [Verificatum library](https://www.verificatum.org/). The mixnet uses the Terelius / Wikström (TW) mixnet

src/main/kotlin/org/cryptobiotic/maths/VectorCiphertext.kt

@@ -13,7 +13,7 @@ data class VectorCiphertext(val group: GroupContext, val elems: List<ElGamalCiph
 
     fun reencrypt(publicKey: ElGamalPublicKey): Pair<VectorCiphertext, VectorQ> {
         val group = publicKey.context
-        val nonces = List(this.nelems) { group.randomElementModQ(minimum = 1) }
+        val nonces = List(this.nelems) { group.randomElementModQ() }
         val reencrypt = this.elems.mapIndexed { idx, text ->
             text.reencrypt(publicKey, nonces[idx])
         }

src/main/kotlin/org/cryptobiotic/maths/VectorQ.kt

@@ -74,7 +74,7 @@ data class VectorQ(val group: GroupContext, val elems: List<ElementModQ> ) {
 
     companion object {
         fun randomQ(group: GroupContext, n: Int): VectorQ {
-            val elems = List(n) { group.randomElementModQ(minimum = 1) }
+            val elems = List(n) { group.randomElementModQ() }
             return VectorQ(group, elems)
         }
 

src/main/kotlin/org/cryptobiotic/mixnet/ShuffleProver.kt

@@ -51,10 +51,9 @@ fun runProof(
     psi: Permutation, // nrows
     nthreads: Int = 10,
 ): ProofOfShuffle {
-    // these are the deterministic nonces and generators that verifier must also be able to generate
-    val generators = getGeneratorsVmn(group, w.size, mixName) // CE n + 1 acc
-    val (pcommit, pnonces) = permutationCommitmentVmn(group, psi, generators)
-    val (prgSeed, e) = makeBatchingVector(group, mixName, generators, pcommit, publicKey, w, wp)
+    val generators = getGeneratorsVmn(group, w.size, mixName) // CE n + 1 acc // deterministic
+    val (pcommit, pnonces) = permutationCommitmentVmn(group, psi, generators) // not shared with Verifier
+    val (prgSeed, e) = makeBatchingVector(group, mixName, generators, pcommit, publicKey, w, wp) // deterministic
 
     val prover = ProverV(   // CE n acc
         group,
@@ -69,7 +68,7 @@ fun runProof(
         psi,
     )
     val pos = prover.commit(nthreads)
-    val challenge = makeChallenge(group, prgSeed, pos)
+    val challenge = makeChallenge(group, prgSeed, pos) // deterministic
     return prover.reply(pos, challenge)
 }
 

src/main/kotlin/org/cryptobiotic/mixnet/ShuffleVerifier.kt

@@ -46,7 +46,7 @@ fun runVerify(
     pos: ProofOfShuffle,
     nthreads: Int = 10,
 ):Boolean {
-    // these are the deterministic nonces and generators that prover must also be able to generate
+    // both prover and verifier must be able to generate deterministically
     val generators = getGeneratorsVmn(group, w.size, pos.mixname) // CE 1 acc n exp
     val (prgSeed, e) = makeBatchingVector(group, pos.mixname, generators, pos.u, publicKey, w, wp)
     val d = group.randomElementModQ() // dont need d
@@ -176,7 +176,7 @@ class PverifyB(
     val challenge: ElementModQ,
     val nthreads: Int = 10,
 ) {
-    val group = h.context
+    val group = h.group
     val nrows = proof.B.nelems
     var isValid = true
 

src/main/kotlin/org/cryptobiotic/mixnet/cli/RunMixnet.kt

@@ -100,7 +100,7 @@ class RunMixnet {
                 ballotStyles = previousConfig.ballotStyles
 
             } else {
-                val seed = mixnet.group.randomElementModQ(minimum = 1)
+                val seed = mixnet.group.randomElementModQ()
                 val nonces = Nonces(seed, mixName) // used for the extra ciphertexts to make even rows
                 val pair = mixnet.readEncryptedBallots(nonces)
                 inputBallots = pair.first

src/test/kotlin/org/cryptobiotic/mixnet/GeneratorsTest.kt

@@ -5,6 +5,7 @@ import org.cryptobiotic.eg.core.ecgroup.EcGroupContext
 import org.cryptobiotic.eg.core.productionGroup
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertTrue
 
 class GeneratorsTest {
     val groups = listOf(
@@ -24,7 +25,8 @@ class GeneratorsTest {
         assertEquals(g1.nelems, g2.nelems)
         g1.elems.forEachIndexed{ idx, g1elem ->
             assertEquals(g1elem, g2.elems[idx])
-            assertEquals(group, g1elem.context)
+            assertEquals(group, g1elem.group)
+            assertTrue( g1elem.isValidElement() )
         }
     }
 

src/test/kotlin/org/cryptobiotic/mixnet/PermutationCommittmentTest.kt

@@ -90,7 +90,7 @@ fun commit(
     generators: VectorP,
     nonce: ElementModQ,
 ): ElementModP {
-    val group = nonce.context
+    val group = nonce.group
     val exp = generators.elems.mapIndexed { idx, it -> it powP psi.of(idx).toElementModQ(group) }
     val vexp = VectorP(group, exp)
     return group.gPowP(nonce) * vexp.product()
@@ -101,7 +101,7 @@ fun commit(
     generators: VectorP,
     nonce: ElementModQ,
 ): ElementModP {
-    val group = nonce.context
+    val group = nonce.group
     val exp = generators.elems.mapIndexed { idx, it -> it powP column[idx].toElementModQ(group) }
     val vexp = VectorP(group, exp)
     return group.gPowP(nonce) * vexp.product()

src/test/kotlin/org/cryptobiotic/mixnet/TimingTest.kt

@@ -131,7 +131,7 @@ class TimingTest {
 
         var stopwatch = Stopwatch()
         repeat(times) {
-            val pows = bases.mapIndexed { idx, it -> it powP nonces[idx] }
+            val pows = bases.mapIndexed { idx, pit -> pit powP nonces[idx] }
             val prod = pows.reduce { a, b -> a * b }
         }
         var duration = stopwatch.stop()

src/test/kotlin/org/cryptobiotic/mixnet/writer/ShuffledBallotRoundtripTest.kt

@@ -70,7 +70,7 @@ class ShuffledBallotRoundtripTest {
         val testOutDir = "${Testing.testOutMixnet}/testBallotWriterFailsBinOverides"
         createDirectories(testOutDir)
         testBallotWriter(group, 100,34, testOutDir, false)
-        val ex = assertFailsWith<AssertionFailedError> {
+        assertFailsWith<AssertionFailedError> {
             testBallotWriter(group, 100,34, testOutDir, true)
         }
     }