Compact committee roots

motes.md

@@ -0,0 +1,42 @@
+* `BLS_WITHDRAWAL_PREFIX`
+  * Why int rather than bytes?
+* `MIN_SEED_LOOKAHEAD`
+  * Is this actually tunable?
+  * If so, what are the reprecussions?
+* `ACTIVATION_EXIT_DELAY`
+  * Reaquaint with purpose
+* AttesterSlashings
+  * `MAX_ATTESTER_SLASHINGS` is 1.
+  * Are there scenarios in which validators can create more effective slashable
+    messages than can be included on chain? For example, Validators split up to
+    create double attestations for checkpoints but different (junk) crosslink
+    data to prevent them from being aggregatable to the fullest
+  * Max is for block size, no?
+* Signature domains
+  * Max 4byte ints
+* `Version` not defined in one of the lists of custom types (2!!). ensure in spec
+* `PendingAttestation`
+  * Don't think `proposer_index` is actually necessary here because effective
+    balance is stable until end of epoch so can do dynamic lookups
+* is_genesis_trigger
+  * only run at ends of blocks to preserve invariant that eth1data.deposit_root
+    is the deposit root at the _end_ of an eth1 block
+* `Attestation` 
+  * why bitfields not together?
+* `Transfer`
+  * replay mechanism... say the slot gets missed and you sign another transfer
+  * in a fork you could include both transfers
+* `get_previous_epoch`
+  * do a once over on the genesis stuff
+* `get_epoch_start_shard`
+  * checking next hinges upon the fact that the validator set for the next
+    epoch is 100% known at the current epoch. Ensure this is the case
+* `get_block_root_at_slot` .. `generate_seed` can be bade into one line
+  function signatures
+* `get_shuffled_index`
+  * I think it should be maybe `assert index_count <= VALIDATOR_REGISTRY_LIMIT`
+  * is the `2**40` special for security of alg? probably.
+
+
+pubkey/privkey g1 vs g2
+

notes.txt

@@ -0,0 +1 @@
+* `BLS_WITHDRAWAL_PREFIX` -- 

specs/core/0_beacon-chain.md

@@ -758,7 +758,7 @@ def get_compact_committees_root(state: BeaconState, epoch: Epoch) -> Hash:
     """
     Return the compact committee root for the current epoch.
     """
-    committees = Vector[CompactCommittee, SHARD_COUNT]()
+    committees = [CompactCommittee() for _ in range(SHARD_COUNT)]
     start_shard = get_epoch_start_shard(state, epoch)
     for committee_number in range(get_epoch_committee_count(state, epoch)):
         shard = (start_shard + committee_number) % SHARD_COUNT
@@ -769,7 +769,7 @@ def get_compact_committees_root(state: BeaconState, epoch: Epoch) -> Hash:
             # `index` (top 6 bytes) + `slashed` (16th bit) + `compact_balance` (bottom 15 bits)
             compact_validator = uint64(index << 16 + validator.slashed << 15 + compact_balance)
             committees[shard].compact_validators.append(compact_validator)
-    return hash_tree_root(committees)
+    return hash_tree_root(Vector[CompactCommittee, SHARD_COUNT](committees))
 ```
 
 ### `generate_seed`