feat(dkg): relax dkg ceremony constraints using new min_shares_num pa…

…rameter

ferveo-python/examples/server_api_precomputed.py

@@ -18,6 +18,7 @@ def gen_eth_addr(i: int) -> str:
 shares_num = 4
 # In precomputed variant, security threshold must be equal to shares_num
 security_threshold = shares_num
+min_shares_num = shares_num
 
 validator_keypairs = [Keypair.random() for _ in range(0, shares_num)]
 validators = [
@@ -35,6 +36,7 @@ def gen_eth_addr(i: int) -> str:
     dkg = Dkg(
         tau=tau,
         shares_num=shares_num,
+        min_shares_num=min_shares_num,
         security_threshold=security_threshold,
         validators=validators,
         me=sender,
@@ -45,6 +47,7 @@ def gen_eth_addr(i: int) -> str:
 dkg = Dkg(
     tau=tau,
     shares_num=shares_num,
+    min_shares_num=min_shares_num,
     security_threshold=security_threshold,
     validators=validators,
     me=validators[0],
@@ -69,6 +72,7 @@ def gen_eth_addr(i: int) -> str:
     dkg = Dkg(
         tau=tau,
         shares_num=shares_num,
+        min_shares_num=min_shares_num,
         security_threshold=security_threshold,
         validators=validators,
         me=validator,

ferveo-python/examples/server_api_simple.py

@@ -15,8 +15,9 @@ def gen_eth_addr(i: int) -> str:
 
 
 tau = 1
-security_threshold = 3
 shares_num = 4
+security_threshold = shares_num - 1
+min_shares_num = shares_num
 validator_keypairs = [Keypair.random() for _ in range(0, shares_num)]
 validators = [
     Validator(gen_eth_addr(i), keypair.public_key())
@@ -33,6 +34,7 @@ def gen_eth_addr(i: int) -> str:
     dkg = Dkg(
         tau=tau,
         shares_num=shares_num,
+        min_shares_num=min_shares_num,
         security_threshold=security_threshold,
         validators=validators,
         me=sender,
@@ -45,6 +47,7 @@ def gen_eth_addr(i: int) -> str:
 dkg = Dkg(
     tau=tau,
     shares_num=shares_num,
+    min_shares_num=min_shares_num,
     security_threshold=security_threshold,
     validators=validators,
     me=me,
@@ -72,6 +75,7 @@ def gen_eth_addr(i: int) -> str:
     dkg = Dkg(
         tau=tau,
         shares_num=shares_num,
+        min_shares_num=min_shares_num,
         security_threshold=security_threshold,
         validators=validators,
         me=validator,

ferveo-wasm/examples/node/src/main.test.ts

@@ -26,6 +26,7 @@ function setupTest() {
   const tau = 1;
   const sharesNum = 4;
   const threshold = Math.floor((sharesNum * 2) / 3);
+  const minSharesNum = sharesNum;
 
   const validatorKeypairs: Keypair[] = [];
   const validators: Validator[] = [];
@@ -40,15 +41,15 @@ function setupTest() {
   // validator, including themselves
   const messages: ValidatorMessage[] = [];
   validators.forEach((sender) => {
-    const dkg = new Dkg(tau, sharesNum, threshold, validators, sender);
+    const dkg = new Dkg(tau, sharesNum, minSharesNum, threshold, validators, sender);
     const transcript = dkg.generateTranscript();
     const message = new ValidatorMessage(sender, transcript);
     messages.push(message);
   });
 
   // Now that every validator holds a dkg instance and a transcript for every other validator,
   // every validator can aggregate the transcripts
-  const dkg = new Dkg(tau, sharesNum, threshold, validators, validators[0]);
+  const dkg = new Dkg(tau, sharesNum, minSharesNum, threshold, validators, validators[0]);
 
   const serverAggregate = dkg.aggregateTranscript(messages);
   expect(serverAggregate.verify(sharesNum, messages)).toBe(true);
@@ -65,6 +66,7 @@ function setupTest() {
   return {
     tau,
     sharesNum,
+    minSharesNum,
     threshold,
     validatorKeypairs,
     validators,
@@ -82,6 +84,7 @@ describe("ferveo-wasm", () => {
     const {
       tau,
       sharesNum,
+      minSharesNum,
       threshold,
       validatorKeypairs,
       validators,
@@ -96,7 +99,7 @@ describe("ferveo-wasm", () => {
     zip(validators, validatorKeypairs).forEach(([validator, keypair]) => {
       expect(validator.publicKey.equals(keypair.publicKey)).toBe(true);
 
-      const dkg = new Dkg(tau, sharesNum, threshold, validators, validator);
+      const dkg = new Dkg(tau, sharesNum, minSharesNum, threshold, validators, validator);
       const aggregate = dkg.aggregateTranscript(messages);
       const isValid = aggregate.verify(sharesNum, messages);
       expect(isValid).toBe(true);
@@ -131,6 +134,7 @@ describe("ferveo-wasm", () => {
     const {
       tau,
       sharesNum,
+      minSharesNum,
       threshold,
       validatorKeypairs,
       validators,
@@ -143,7 +147,7 @@ describe("ferveo-wasm", () => {
     // Having aggregated the transcripts, the validators can now create decryption shares
     const decryptionShares: DecryptionSharePrecomputed[] = [];
     zip(validators, validatorKeypairs).forEach(([validator, keypair]) => {
-      const dkg = new Dkg(tau, sharesNum, threshold, validators, validator);
+      const dkg = new Dkg(tau, sharesNum, minSharesNum, threshold, validators, validator);
       const aggregate = dkg.aggregateTranscript(messages);
       const isValid = aggregate.verify(sharesNum, messages);
       expect(isValid).toBe(true);

ferveo-wasm/tests/node.rs

@@ -8,8 +8,9 @@ use wasm_bindgen_test::*;
 
 type TestSetup = (
     u32,
-    usize,
-    usize,
+    u32,
+    u32,
+    u32,
     Vec<Keypair>,
     Vec<Validator>,
     ValidatorArray,
@@ -21,11 +22,13 @@ type TestSetup = (
 
 fn setup_dkg() -> TestSetup {
     let tau = 1;
-    let shares_num = 16;
+    let shares_num: u32 = 16;
     let security_threshold = shares_num * 2 / 3;
+    let min_shares_num = shares_num;
 
-    let validator_keypairs =
-        (0..shares_num).map(gen_keypair).collect::<Vec<Keypair>>();
+    let validator_keypairs = (0..shares_num as usize)
+        .map(gen_keypair)
+        .collect::<Vec<Keypair>>();
     let validators = validator_keypairs
         .iter()
         .enumerate()
@@ -38,8 +41,9 @@ fn setup_dkg() -> TestSetup {
     let messages = validators.iter().map(|sender| {
         let dkg = Dkg::new(
             tau,
-            shares_num as u32,
-            security_threshold as u32,
+            shares_num,
+            min_shares_num,
+            security_threshold,
             &validators_js,
             sender,
         )
@@ -54,8 +58,9 @@ fn setup_dkg() -> TestSetup {
 
     let mut dkg = Dkg::new(
         tau,
-        shares_num as u32,
-        security_threshold as u32,
+        shares_num,
+        min_shares_num,
+        security_threshold,
         &validators_js,
         &validators[0],
     )
@@ -81,6 +86,7 @@ fn setup_dkg() -> TestSetup {
     (
         tau,
         shares_num,
+        min_shares_num,
         security_threshold,
         validator_keypairs,
         validators,
@@ -97,6 +103,7 @@ fn tdec_simple() {
     let (
         tau,
         shares_num,
+        min_shares_num,
         security_threshold,
         validator_keypairs,
         validators,
@@ -112,8 +119,9 @@ fn tdec_simple() {
         .map(|(validator, keypair)| {
             let mut dkg = Dkg::new(
                 tau,
-                shares_num as u32,
-                security_threshold as u32,
+                shares_num,
+                min_shares_num,
+                security_threshold,
                 &validators_js,
                 &validator,
             )
@@ -151,6 +159,7 @@ fn tdec_precomputed() {
     let (
         tau,
         shares_num,
+        min_shares_num,
         security_threshold,
         validator_keypairs,
         validators,
@@ -166,8 +175,9 @@ fn tdec_precomputed() {
         .map(|(validator, keypair)| {
             let mut dkg = Dkg::new(
                 tau,
-                shares_num as u32,
-                security_threshold as u32,
+                shares_num,
+                min_shares_num,
+                security_threshold,
                 &validators_js,
                 &validator,
             )

ferveo/benches/benchmarks/validity_checks.rs

@@ -45,11 +45,7 @@ fn setup_dkg(
     let me = validators[validator].clone();
     PubliclyVerifiableDkg::new(
         &validators,
-        &DkgParams {
-            tau: 0,
-            security_threshold: shares_num / 3,
-            shares_num,
-        },
+        &DkgParams::new(0, shares_num / 3, shares_num, shares_num).unwrap(),
         &me,
     )
     .expect("Setup failed")

ferveo/examples/bench_primitives_size.rs

@@ -80,11 +80,7 @@ fn setup_dkg(
     let me = validators[validator].clone();
     PubliclyVerifiableDkg::new(
         &validators,
-        &DkgParams {
-            tau: 0,
-            security_threshold,
-            shares_num,
-        },
+        &DkgParams::new(0, security_threshold, shares_num, shares_num).unwrap(),
         &me,
     )
     .expect("Setup failed")