Fast Confirmation Rule

configs/mainnet.yaml

@@ -245,3 +245,7 @@ BLOB_SCHEDULE:
     MAX_BLOBS_PER_BLOCK: 15
   - EPOCH: 419072  # January 7, 2026, 01:01:11am UTC
     MAX_BLOBS_PER_BLOCK: 21
+
+# Fast Confirmation Rule
+# ---------------------------------------------------------------
+CONFIRMATION_BYZANTINE_THRESHOLD: 25

configs/minimal.yaml

@@ -238,3 +238,7 @@ MAX_BYTES_PER_INCLUSION_LIST: 8192
 # ---------------------------------------------------------------
 
 BLOB_SCHEDULE: []
+
+# Fast Confirmation Rule
+# ---------------------------------------------------------------
+CONFIRMATION_BYZANTINE_THRESHOLD: 25

fork_choice/safe-block.md

@@ -20,13 +20,10 @@ This section describes an algorithm to find a safe block.
 
 ```python
 def get_safe_beacon_block_root(store: Store) -> Root:
-    # Use most recent justified block as a stopgap
-    return store.justified_checkpoint.root
+    # Use the most recent confirmed_root determined by the FCR algorithm
+    return store.confirmed_root
 ```
 
-*Note*: Currently safe block algorithm simply returns
-`store.justified_checkpoint.root` and is meant to be improved in the future.
-
 ## `get_safe_execution_block_hash`
 
 ```python

specs/_features/eip7805/fork-choice.md

@@ -119,6 +119,12 @@ class Store(object):
     unrealized_justified_checkpoint: Checkpoint
     unrealized_finalized_checkpoint: Checkpoint
     proposer_boost_root: Root
+    confirmed_root: Root
+    previous_epoch_observed_justified_checkpoint: Checkpoint
+    current_epoch_observed_justified_checkpoint: Checkpoint
+    previous_epoch_greatest_unrealized_checkpoint: Checkpoint
+    previous_slot_head: Root
+    current_slot_head: Root
     equivocating_indices: Set[ValidatorIndex]
     blocks: Dict[Root, BeaconBlock] = field(default_factory=dict)
     block_states: Dict[Root, BeaconState] = field(default_factory=dict)
@@ -148,6 +154,12 @@ def get_forkchoice_store(anchor_state: BeaconState, anchor_block: BeaconBlock) -
         unrealized_justified_checkpoint=justified_checkpoint,
         unrealized_finalized_checkpoint=finalized_checkpoint,
         proposer_boost_root=proposer_boost_root,
+        confirmed_root=anchor_root,
+        previous_epoch_observed_justified_checkpoint=justified_checkpoint,
+        current_epoch_observed_justified_checkpoint=justified_checkpoint,
+        previous_epoch_greatest_unrealized_checkpoint=justified_checkpoint,
+        previous_slot_head=anchor_root,
+        current_slot_head=anchor_root,
         equivocating_indices=set(),
         blocks={anchor_root: copy(anchor_block)},
         block_states={anchor_root: copy(anchor_state)},

specs/gloas/fork-choice.md

@@ -33,6 +33,7 @@
   - [Modified `is_head_late`](#modified-is_head_late)
   - [Modified `is_head_weak`](#modified-is_head_weak)
   - [Modified `is_parent_strong`](#modified-is_parent_strong)
+  - [Modified `get_latest_message_epoch`](#modified-get_latest_message_epoch)
   - [Modified `get_attestation_due_ms`](#modified-get_attestation_due_ms)
   - [Modified `get_aggregate_due_ms`](#modified-get_aggregate_due_ms)
   - [Modified `get_sync_message_due_ms`](#modified-get_sync_message_due_ms)
@@ -130,6 +131,12 @@ class Store(object):
     unrealized_justified_checkpoint: Checkpoint
     unrealized_finalized_checkpoint: Checkpoint
     proposer_boost_root: Root
+    confirmed_root: Root
+    previous_epoch_observed_justified_checkpoint: Checkpoint
+    current_epoch_observed_justified_checkpoint: Checkpoint
+    previous_epoch_greatest_unrealized_checkpoint: Checkpoint
+    previous_slot_head: Root
+    current_slot_head: Root
     equivocating_indices: Set[ValidatorIndex]
     blocks: Dict[Root, BeaconBlock] = field(default_factory=dict)
     block_states: Dict[Root, BeaconState] = field(default_factory=dict)
@@ -163,6 +170,12 @@ def get_forkchoice_store(anchor_state: BeaconState, anchor_block: BeaconBlock) -
         unrealized_justified_checkpoint=justified_checkpoint,
         unrealized_finalized_checkpoint=finalized_checkpoint,
         proposer_boost_root=proposer_boost_root,
+        confirmed_root=anchor_root,
+        previous_epoch_observed_justified_checkpoint=justified_checkpoint,
+        current_epoch_observed_justified_checkpoint=justified_checkpoint,
+        previous_epoch_greatest_unrealized_checkpoint=justified_checkpoint,
+        previous_slot_head=anchor_root,
+        current_slot_head=anchor_root,
         equivocating_indices=set(),
         blocks={anchor_root: copy(anchor_block)},
         block_states={anchor_root: copy(anchor_state)},
@@ -633,6 +646,13 @@ def is_parent_strong(store: Store, root: Root) -> bool:
     return parent_weight > parent_threshold
 ```
 
+### Modified `get_latest_message_epoch`
+
+```python
+def get_latest_message_epoch(latest_message: LatestMessage) -> Epoch:
+    return compute_epoch_at_slot(latest_message.slot)
+```
+
 ### Modified `get_attestation_due_ms`
 
 ```python