Introduce multi-attempt ouroboros to avoid gaps

ziesha-network · May 17, 2023 · 699576a · 699576a
1 parent 281ef39
commit 699576a
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Showing 6 changed files with 25 additions and 18 deletions.
diff --git a/src/blockchain/mod.rs b/src/blockchain/mod.rs
@@ -560,7 +560,13 @@ impl<K: KvStore> Blockchain<K> for KvStoreChain<K> {
         if let Some(chance) = stakers.get(&addr) {
             if let Some(staker_info) = self.get_staker(addr.clone())? {
                 if Into::<f32>::into(proof.vrf_output.clone()) <= *chance {
-                    let preimage = format!("{}-{}-{}", hex::encode(randomness), epoch, slot);
+                    let preimage = format!(
+                        "{}-{}-{}-{}",
+                        hex::encode(randomness),
+                        epoch,
+                        slot,
+                        proof.attempt
+                    );
 
                     return Ok(Vrf::verify(
                         &staker_info.vrf_pub_key,
@@ -578,6 +584,7 @@ impl<K: KvStore> Blockchain<K> for KvStoreChain<K> {
         timestamp: u32,
         wallet: &TxBuilder,
     ) -> Result<Option<ValidatorProof>, BlockchainError> {
+        const MAX_ATTEMPTS: u32 = 3;
         let (epoch, slot) = self.epoch_slot(timestamp);
         let randomness = self.epoch_randomness()?;
         let stakers = self.get_stakers()?;
@@ -586,13 +593,17 @@ impl<K: KvStore> Blockchain<K> for KvStoreChain<K> {
             .into_iter()
             .map(|(k, v)| (k, (u64::from(v) as f64 / sum_stakes as f64) as f32))
             .collect();
-        if let Some(chance) = stakers.get(&wallet.get_address()) {
-            let (vrf_output, vrf_proof) = wallet.generate_random(randomness, epoch, slot);
-            if Into::<f32>::into(vrf_output.clone()) <= *chance {
-                return Ok(Some(ValidatorProof {
-                    vrf_output,
-                    vrf_proof,
-                }));
+        for attempt in 0..MAX_ATTEMPTS {
+            if let Some(chance) = stakers.get(&wallet.get_address()) {
+                let (vrf_output, vrf_proof) =
+                    wallet.generate_random(randomness, epoch, slot, attempt);
+                if Into::<f32>::into(vrf_output.clone()) <= *chance {
+                    return Ok(Some(ValidatorProof {
+                        attempt,
+                        vrf_output,
+                        vrf_proof,
+                    }));
+                }
             }
         }
         Ok(None)

diff --git a/src/client/messages.rs b/src/client/messages.rs
@@ -36,7 +36,6 @@ pub struct GetStatsResponse {
     pub version: String,
     pub network: String,
     pub validator_claim: Option<ValidatorClaim>,
-    pub random_number: f32,
 }
 
 #[derive(Deserialize, Serialize, Debug, Clone)]

diff --git a/src/core/header.rs b/src/core/header.rs
@@ -4,6 +4,7 @@ use crate::crypto::{SignatureScheme, VerifiableRandomFunction};
 // A proof that you are the validator for this block
 #[derive(Clone, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize, Hash)]
 pub struct ValidatorProof<V: VerifiableRandomFunction> {
+    pub attempt: u32,
     pub vrf_output: V::Out,
     pub vrf_proof: V::Proof,
 }

diff --git a/src/node/api/get_stats.rs b/src/node/api/get_stats.rs
@@ -12,12 +12,6 @@ pub async fn get_stats<K: KvStore, B: Blockchain<K>>(
     let context = context.read().await;
     let ts = context.network_timestamp();
     let (epoch, slot) = context.blockchain.epoch_slot(ts);
-    let randomness = context.blockchain.epoch_randomness()?;
-    let random_number: f32 = context
-        .validator_wallet
-        .generate_random(randomness, epoch, slot)
-        .0
-        .into();
 
     Ok(GetStatsResponse {
         social_profiles: context.social_profiles.clone(),
@@ -32,6 +26,5 @@ pub async fn get_stats<K: KvStore, B: Blockchain<K>>(
         version: env!("CARGO_PKG_VERSION").into(),
         network: context.network.clone(),
         validator_claim: context.validator_claim.clone(),
-        random_number,
     })
 }
diff --git a/src/node/context.rs b/src/node/context.rs
@@ -103,7 +103,9 @@ impl<K: KvStore, B: Blockchain<K>> NodeContext<K, B> {
                 let (epoch_curr, slot_curr) = self.blockchain.epoch_slot(curr_claim.timestamp);
                 let (epoch_req, slot_req) = self.blockchain.epoch_slot(claim.timestamp);
                 if epoch_curr == epoch_req && slot_curr == slot_req {
-                    return Ok(false);
+                    if claim.proof.attempt >= curr_claim.proof.attempt {
+                        return Ok(false);
+                    }
                 }
             }
             let ts = self.network_timestamp();

diff --git a/src/wallet/tx_builder.rs b/src/wallet/tx_builder.rs
@@ -148,13 +148,14 @@ impl TxBuilder {
         randomness: <Hasher as Hash>::Output,
         epoch: u32,
         slot: u32,
+        attempt: u32,
     ) -> (
         <Vrf as VerifiableRandomFunction>::Out,
         <Vrf as VerifiableRandomFunction>::Proof,
     ) {
         Vrf::sign(
             &self.vrf_private_key,
-            format!("{}-{}-{}", hex::encode(randomness), epoch, slot).as_bytes(),
+            format!("{}-{}-{}-{}", hex::encode(randomness), epoch, slot, attempt).as_bytes(),
         )
     }
     pub fn register_validator(