feat(slasher): per-slot data-withholding watcher (A-523, A-525)

l1-contracts/src/core/slashing/SlashingProposer.sol

@@ -50,12 +50,11 @@ import {SafeCast} from "@oz/utils/math/SafeCast.sol";
  *
  *      About SLASH_OFFSET_IN_ROUNDS:
  *      - This offset gives us time to detect an offense and then vote on it in a later
- *        round. For instance, an `VALID_EPOCH_PRUNED` offense for epoch N is only triggered after
- *        `PROOF_SUBMISSION_WINDOW` epochs. Consider the following:
- *        - Epoch 1 is valid
- *        - At the end of epoch 3, the proof for 1 has not landed, so epoch 1 is pruned
- *        - Network decides to slash the committee of epoch 1
- *        - This means that only starting from epoch 4 we should be voting for slashing the committee of epoch 1
+ *        round. For instance, a `DATA_WITHHOLDING` offense for slot S is only triggered after
+ *        `DATA_WITHHOLDING_TOLERANCE_SLOTS` slots. Consider:
+ *        - Slot S publishes a checkpoint
+ *        - At slot S + tolerance, observers find missing data and want to slash the attesters
+ *        - Voting on that slash needs to happen in a round that starts after detection
  *      - In terms of voting, this parameter means that in round R we are voting for the committee of epochs starting
  *        from (R - SLASH_OFFSET_IN_ROUNDS) * ROUND_SIZE_IN_EPOCHS.
  *      - For example, with SLASH_OFFSET_IN_ROUNDS=2, ROUND_SIZE=10, and EPOCH_DURATION=2

spartan/aztec-node/templates/_pod-template.yaml

@@ -217,14 +217,14 @@ spec:
         - name: SLASH_VALIDATORS_NEVER
           value: {{ join "," .Values.node.slash.validatorsNever | quote }}
         {{- end }}
-        {{- if .Values.node.slash.prunePenalty }}
-        - name: SLASH_PRUNE_PENALTY
-          value: {{ .Values.node.slash.prunePenalty | quote }}
-        {{- end }}
         {{- if .Values.node.slash.dataWithholdingPenalty }}
         - name: SLASH_DATA_WITHHOLDING_PENALTY
           value: {{ .Values.node.slash.dataWithholdingPenalty | quote }}
         {{- end }}
+        {{- if .Values.node.slash.dataWithholdingToleranceSlots }}
+        - name: SLASH_DATA_WITHHOLDING_TOLERANCE_SLOTS
+          value: {{ .Values.node.slash.dataWithholdingToleranceSlots | quote }}
+        {{- end }}
         {{- if .Values.node.slash.inactivityPenalty }}
         - name: SLASH_INACTIVITY_PENALTY
           value: {{ .Values.node.slash.inactivityPenalty | quote }}

spartan/aztec-node/values.yaml

@@ -148,8 +148,8 @@ node:
     validatorsAlways: []
     validatorsNever: []
     # Penalty amounts for different offense types
-    prunePenalty: ""
     dataWithholdingPenalty: ""
+    dataWithholdingToleranceSlots: ""
     inactivityPenalty: ""
     inactivityTargetPercentage: ""
     invalidBlockPenalty: ""

spartan/environments/network-defaults.yml

@@ -119,10 +119,10 @@ slasher: &slasher
   SLASH_MAX_PAYLOAD_SIZE: 80
   # Rounds to look back when executing slashes.
   SLASH_EXECUTE_ROUNDS_LOOK_BACK: 4
-  # Penalty for slashing validators of a valid pruned epoch.
-  SLASH_PRUNE_PENALTY: 10e18
   # Penalty for data withholding.
   SLASH_DATA_WITHHOLDING_PENALTY: 10e18
+  # L2 slots to wait after a checkpoint's slot before declaring its txs missing.
+  SLASH_DATA_WITHHOLDING_TOLERANCE_SLOTS: 3
   # Missed attestation percentage to trigger inactivity slash (0, 1].
   SLASH_INACTIVITY_TARGET_PERCENTAGE: 0.9
   # Consecutive epochs a validator must be inactive before slashing.
@@ -233,7 +233,6 @@ networks:
     PUBLIC_OTEL_EXPORTER_OTLP_METRICS_ENDPOINT: ""
     PUBLIC_OTEL_COLLECT_FROM: ""
     # Slasher penalties
-    SLASH_PRUNE_PENALTY: 10e18
     SLASH_DATA_WITHHOLDING_PENALTY: 10e18
     SLASH_INACTIVITY_TARGET_PERCENTAGE: 0.9
     SLASH_INACTIVITY_CONSECUTIVE_EPOCH_THRESHOLD: 1
@@ -278,7 +277,6 @@ networks:
     P2P_MAX_PENDING_TX_COUNT: 1000
     P2P_TX_POOL_DELETE_TXS_AFTER_REORG: true
     # Slasher penalties
-    SLASH_PRUNE_PENALTY: 10e18
     SLASH_DATA_WITHHOLDING_PENALTY: 10e18
     SLASH_INACTIVITY_TARGET_PERCENTAGE: 0.9
     SLASH_INACTIVITY_CONSECUTIVE_EPOCH_THRESHOLD: 1
@@ -337,7 +335,6 @@ networks:
     PUBLIC_OTEL_COLLECT_FROM: ""
     ENABLE_VERSION_CHECK: false
     # Slasher penalties - more lenient initially
-    SLASH_PRUNE_PENALTY: 0
     SLASH_DATA_WITHHOLDING_PENALTY: 0
     SLASH_INACTIVITY_TARGET_PERCENTAGE: 0.8
     SLASH_INACTIVITY_CONSECUTIVE_EPOCH_THRESHOLD: 2

spartan/scripts/deploy_network.sh

@@ -586,8 +586,8 @@ PROVER_PUBLISHERS_PER_PROVER = ${PUBLISHERS_PER_PROVER}
 SENTINEL_ENABLED = ${SENTINEL_ENABLED:-null}
 SLASH_INACTIVITY_TARGET_PERCENTAGE = ${SLASH_INACTIVITY_TARGET_PERCENTAGE:-null}
 SLASH_INACTIVITY_PENALTY = ${SLASH_INACTIVITY_PENALTY:-null}
-SLASH_PRUNE_PENALTY = ${SLASH_PRUNE_PENALTY:-null}
 SLASH_DATA_WITHHOLDING_PENALTY = ${SLASH_DATA_WITHHOLDING_PENALTY:-null}
+SLASH_DATA_WITHHOLDING_TOLERANCE_SLOTS = ${SLASH_DATA_WITHHOLDING_TOLERANCE_SLOTS:-null}
 SLASH_PROPOSE_INVALID_ATTESTATIONS_PENALTY = ${SLASH_PROPOSE_INVALID_ATTESTATIONS_PENALTY:-null}
 SLASH_DUPLICATE_PROPOSAL_PENALTY = ${SLASH_DUPLICATE_PROPOSAL_PENALTY:-null}
 SLASH_DUPLICATE_ATTESTATION_PENALTY = ${SLASH_DUPLICATE_ATTESTATION_PENALTY:-null}

spartan/terraform/deploy-aztec-infra/main.tf

@@ -200,8 +200,8 @@ locals {
     "validator.sentinel.enabled"                                  = var.SENTINEL_ENABLED
     "validator.slash.inactivityTargetPercentage"                  = var.SLASH_INACTIVITY_TARGET_PERCENTAGE
     "validator.slash.inactivityPenalty"                           = var.SLASH_INACTIVITY_PENALTY
-    "validator.slash.prunePenalty"                                = var.SLASH_PRUNE_PENALTY
     "validator.slash.dataWithholdingPenalty"                      = var.SLASH_DATA_WITHHOLDING_PENALTY
+    "validator.slash.dataWithholdingToleranceSlots"               = var.SLASH_DATA_WITHHOLDING_TOLERANCE_SLOTS
     "validator.slash.proposeInvalidAttestationsPenalty"           = var.SLASH_PROPOSE_INVALID_ATTESTATIONS_PENALTY
     "validator.slash.duplicateProposalPenalty"                    = var.SLASH_DUPLICATE_PROPOSAL_PENALTY
     "validator.slash.duplicateAttestationPenalty"                 = var.SLASH_DUPLICATE_ATTESTATION_PENALTY

spartan/terraform/deploy-aztec-infra/variables.tf

@@ -466,14 +466,14 @@ variable "SLASH_INACTIVITY_PENALTY" {
   nullable    = true
 }
 
-variable "SLASH_PRUNE_PENALTY" {
-  description = "The slash prune penalty"
+variable "SLASH_DATA_WITHHOLDING_PENALTY" {
+  description = "The slash data withholding penalty"
   type        = string
   nullable    = true
 }
 
-variable "SLASH_DATA_WITHHOLDING_PENALTY" {
-  description = "The slash data withholding penalty"
+variable "SLASH_DATA_WITHHOLDING_TOLERANCE_SLOTS" {
+  description = "L2 slots to wait after a checkpoint slot before slashing for data withholding"
   type        = string
   nullable    = true
 }

yarn-project/aztec-node/src/aztec-node/server.ts

@@ -42,7 +42,7 @@ import {
 import { PublicProcessorFactory } from '@aztec/simulator/server';
 import {
   AttestationsBlockWatcher,
-  EpochPruneWatcher,
+  DataWithholdingWatcher,
   type SlasherClientInterface,
   type Watcher,
   createSlasher,
@@ -174,7 +174,7 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, AztecNodeDeb
     protected readonly proverNode: ProverNode | undefined,
     protected readonly slasherClient: SlasherClientInterface | undefined,
     protected readonly validatorsSentinel: Sentinel | undefined,
-    protected readonly epochPruneWatcher: EpochPruneWatcher | undefined,
+    protected readonly dataWithholdingWatcher: DataWithholdingWatcher | undefined,
     protected readonly attestationsBlockWatcher: AttestationsBlockWatcher | undefined,
     protected readonly l1ChainId: number,
     protected readonly version: number,
@@ -719,7 +719,7 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, AztecNodeDeb
       await p2pClient.start();
 
       let validatorsSentinel: Awaited<ReturnType<typeof createSentinel>> | undefined;
-      let epochPruneWatcher: EpochPruneWatcher | undefined;
+      let dataWithholdingWatcher: DataWithholdingWatcher | undefined;
       let attestationsBlockWatcher: AttestationsBlockWatcher | undefined;
 
       if (!proverOnly) {
@@ -728,16 +728,16 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, AztecNodeDeb
           watchers.push(validatorsSentinel);
         }
 
-        if (config.slashPrunePenalty > 0n || config.slashDataWithholdingPenalty > 0n) {
-          epochPruneWatcher = new EpochPruneWatcher(
-            archiver,
-            archiver,
+        if (config.slashDataWithholdingPenalty > 0n) {
+          dataWithholdingWatcher = new DataWithholdingWatcher(
             epochCache,
+            archiver,
             p2pClient.getTxProvider(),
-            validatorCheckpointsBuilder,
+            p2pClient,
+            { chainId: config.l1ChainId, rollupAddress: config.l1Contracts.rollupAddress },
             config,
           );
-          watchers.push(epochPruneWatcher);
+          watchers.push(dataWithholdingWatcher);
         }
 
         // We assume we want to slash for invalid attestations unless all max penalties are set to 0
@@ -755,9 +755,9 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, AztecNodeDeb
             await validatorsSentinel.start();
             started.push(validatorsSentinel);
           }
-          if (epochPruneWatcher) {
-            await epochPruneWatcher.start();
-            started.push(epochPruneWatcher);
+          if (dataWithholdingWatcher) {
+            await dataWithholdingWatcher.start();
+            started.push(dataWithholdingWatcher);
           }
           if (attestationsBlockWatcher) {
             await attestationsBlockWatcher.start();
@@ -892,7 +892,7 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, AztecNodeDeb
         proverNode,
         slasherClient,
         validatorsSentinel,
-        epochPruneWatcher,
+        dataWithholdingWatcher,
         attestationsBlockWatcher,
         ethereumChain.chainInfo.id,
         config.rollupVersion,
@@ -1171,7 +1171,7 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, AztecNodeDeb
     this.log.info(`Stopping Aztec Node`);
     await tryStop(this.attestationsBlockWatcher);
     await tryStop(this.validatorsSentinel);
-    await tryStop(this.epochPruneWatcher);
+    await tryStop(this.dataWithholdingWatcher);
     await tryStop(this.slasherClient);
     await Promise.all([tryStop(this.peerProofVerifier), tryStop(this.rpcProofVerifier)]);
     await tryStop(this.sequencer);

yarn-project/aztec-node/src/test/index.ts

@@ -1,7 +1,7 @@
 import type { EpochCacheInterface } from '@aztec/epoch-cache';
 import type { P2P } from '@aztec/p2p';
 import { SequencerClient } from '@aztec/sequencer-client';
-import { EpochPruneWatcher, type SlasherClientInterface } from '@aztec/slasher';
+import { DataWithholdingWatcher, type SlasherClientInterface } from '@aztec/slasher';
 import type { L2BlockSource } from '@aztec/stdlib/block';
 import type { ContractDataSource } from '@aztec/stdlib/contract';
 import type { L2LogsSource, Service, WorldStateSynchronizer } from '@aztec/stdlib/interfaces/server';
@@ -23,7 +23,7 @@ export declare class TestAztecNodeService extends AztecNodeService {
   declare public sequencer: SequencerClient | undefined;
   declare public slasherClient: SlasherClientInterface | undefined;
   declare public validatorsSentinel: Sentinel | undefined;
-  declare public epochPruneWatcher: EpochPruneWatcher | undefined;
+  declare public dataWithholdingWatcher: DataWithholdingWatcher | undefined;
   declare public l1ChainId: number;
   declare public version: number;
   declare public globalVariableBuilder: GlobalVariableBuilderInterface;