feat(core): add Sailfish++ protocol variant

README.md

@@ -19,15 +19,18 @@ Three versions of Starfish are available in this repository:
 
 - **`starfish-speed`**: Strong-vote optimistic variant
   - Uses strong votes for optimistic transaction sequencing
-  - Lower latency when validators have same acknowledgments as a leader. Matches
+  - Lower latency when validators have same acknowledgments as a leader
 
 - **`starfish-bls`**: BLS-optimized variant
   - Uses BLS aggregate signatures to reduce communication complexity for header metadata
   - Embeds compact aggregate certificates (round, leader, data availability) in block headers
   - Async BLS verification service offloads signature processing from the critical path
 
-The repository also supports other partially synchronous uncertified DAG-based consensus protocols:
+The repository also supports other partially synchronous DAG-based consensus protocols:
 
+- **`sailfish++`**: Implementation based on [SFSailfish](https://arxiv.org/abs/2505.02761) ("Optimistic, Signature-Free Reliable Broadcast and Its Applications", CCS'25).
+A certified DAG protocol using signature-free optimistic reliable broadcast (RBC) for vertex certification.
+Achieves 2-round optimistic commit latency with authentication derived from TCP channels rather than cryptographic signatures.
 - **`mysticeti`**: Implementation of [Mysticeti](https://www.cs.cornell.edu/~babel/papers/mysticeti.pdf).
 Validators use a bandwidth efficient pull-based block dissemination strategy:
 they push their own blocks and request the peers about missing ancestors only.
@@ -37,6 +40,17 @@ pushing all unknown history of blocks to their peers.
 Due to the push strategy, Cordial Miners can tolerate Byzantine attacks,
 but it is overall a less scalable solution.
 
+### Protocol Comparison
+
+| Feature | Starfish | Starfish-Speed | Starfish-BLS | Sailfish++ | Mysticeti | Cordial Miners |
+|---|---|---|---|---|---|---|
+| DAG type | Uncertified | Uncertified | Uncertified | Certified (RBC) | Uncertified | Uncertified |
+| Commit latency (rounds) | 3 | 3 (opt: 2) | 3 | 2 | 3 | 3 |
+| Transaction encoding | Reed-Solomon | Reed-Solomon | Reed-Solomon | Full blocks | Full blocks | Full blocks |
+| Dissemination default | Push-causal | Push-causal | Push-causal | Pull | Pull | Push-causal |
+| Certification mechanism | None | None | BLS aggregate sigs | Signature-free RBC | None | None |
+| Acknowledgment references | Yes | Yes | Yes (DAC) | No | No | No |
+
 ## Key Features of Starfish
 
 - Starfish is a Byzantine Fault Tolerant protocol capable of tolerating up to 1/3 of Byzantine nodes in a partially synchronous network.
@@ -182,7 +196,7 @@ NUM_VALIDATORS=10 DESIRED_TPS=1000 CONSENSUS=starfish-speed \
 |---|---|---|
 | `NUM_VALIDATORS` | 10 | Number of validators (recommend < physical cores, max 128) |
 | `DESIRED_TPS` | 1000 | Target transactions per second |
-| `CONSENSUS` | starfish-speed | Protocol: `starfish`, `starfish-speed`, `starfish-bls`, `cordial-miners`, `mysticeti` |
+| `CONSENSUS` | starfish-speed | Protocol: `starfish`, `starfish-speed`, `starfish-bls`, `sailfish-pp`, `cordial-miners`, `mysticeti` |
 | `NUM_BYZANTINE_NODES` | 0 | Must be < `NUM_VALIDATORS / 3` |
 | `BYZANTINE_STRATEGY` | random-drop | See [Byzantine strategies](#byzantine-strategies) |
 | `TEST_TIME` | 3000 | Duration in seconds |

crates/starfish-core/src/bls_certificate_aggregator.rs

@@ -1100,6 +1100,7 @@ mod tests {
             None,
             None,
             None,
+            None,
         )
     }
 

crates/starfish-core/src/broadcaster.rs

@@ -71,7 +71,7 @@ impl BroadcasterParameters {
         causal_push_shard_round_lag: RoundNumber,
     ) -> Self {
         match consensus_protocol {
-            ConsensusProtocol::Mysticeti => Self {
+            ConsensusProtocol::Mysticeti | ConsensusProtocol::SailfishPlusPlus => Self {
                 batch_own_block_size: committee_size,
                 batch_other_block_size: 3 * committee_size,
                 batch_shard_size: 3 * committee_size,
@@ -412,7 +412,9 @@ where
                     .await
                     .ok()?;
             }
-            ConsensusProtocol::Mysticeti | ConsensusProtocol::CordialMiners => {
+            ConsensusProtocol::Mysticeti
+            | ConsensusProtocol::CordialMiners
+            | ConsensusProtocol::SailfishPlusPlus => {
                 let all_blocks = self.inner.dag_state.get_storage_blocks(&block_references);
 
                 let mut blocks = Vec::new();
@@ -814,9 +816,9 @@ fn push_transport_format(consensus_protocol: ConsensusProtocol) -> PushOtherBloc
         ConsensusProtocol::Starfish
         | ConsensusProtocol::StarfishSpeed
         | ConsensusProtocol::StarfishBls => PushOtherBlocksFormat::HeadersAndShards,
-        ConsensusProtocol::CordialMiners | ConsensusProtocol::Mysticeti => {
-            PushOtherBlocksFormat::FullBlocks
-        }
+        ConsensusProtocol::CordialMiners
+        | ConsensusProtocol::Mysticeti
+        | ConsensusProtocol::SailfishPlusPlus => PushOtherBlocksFormat::FullBlocks,
     }
 }