From 9f4ae4c6eeb281a76788900ae2552a59a7f55eb1 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 21 Oct 2022 17:33:55 -0700
Subject: [PATCH] Update validator spec with `SignedBeaconBlockAndBlobsSidecar`

---
 specs/eip4844/p2p-interface.md |  6 +++---
 specs/eip4844/validator.md     | 33 +++++++++++++--------------------
 2 files changed, 16 insertions(+), 23 deletions(-)

diff --git a/specs/eip4844/p2p-interface.md b/specs/eip4844/p2p-interface.md
index 735230027..2162ab161 100644
--- a/specs/eip4844/p2p-interface.md
+++ b/specs/eip4844/p2p-interface.md
@@ -18,7 +18,7 @@ The specification of these changes continues in the same format as the network s
   - [The gossip domain: gossipsub](#the-gossip-domain-gossipsub)
     - [Topics and messages](#topics-and-messages)
       - [Global topics](#global-topics)
-        - [`beacon_block_and_blob_sidecar`](#beacon_block_and_blob_sidecar)
+        - [`beacon_block_and_blobs_sidecar`](#beacon_block_and_blobs_sidecar)
     - [Transitioning the gossip](#transitioning-the-gossip)
   - [The Req/Resp domain](#the-reqresp-domain)
     - [Messages](#messages)
@@ -83,14 +83,14 @@ The new topics along with the type of the `data` field of a gossipsub message ar
 
 | Name | Message Type |
 | - | - |
-| `beacon_block_and_blob_sidecar` | `SignedBeaconBlockAndBlobsSidecar` (new) |
+| `beacon_block_and_blobs_sidecar` | `SignedBeaconBlockAndBlobsSidecar` (new) |
 
 
 #### Global topics
 
 EIP4844 introduces a new global topic for beacon block and blobs-sidecars.
 
-##### `beacon_block_and_blob_sidecar`
+##### `beacon_block_and_blobs_sidecar`
 
 This topic is used to propagate new signed and coupled beacon blocks and blobs sidecars to all nodes on the networks.
 
diff --git a/specs/eip4844/validator.md b/specs/eip4844/validator.md
index e1bcf9564..18623659a 100644
--- a/specs/eip4844/validator.md
+++ b/specs/eip4844/validator.md
@@ -192,9 +192,9 @@ def get_blobs_and_kzg_commitments(payload_id: PayloadId) -> Tuple[Sequence[BLSFi
 ## Beacon chain responsibilities
 
 All validator responsibilities remain unchanged other than those noted below.
-Namely, the blob handling and the addition of `BlobsSidecar`.
+Namely, the blob handling and the addition of `SignedBeaconBlockAndBlobsSidecar`.
 
-### Block proposal
+### Block and sidecar proposal
 
 #### Constructing the `BeaconBlockBody`
 
@@ -218,13 +218,16 @@ def validate_blobs_and_kzg_commitments(execution_payload: ExecutionPayload,
 
 3. If valid, set `block.body.blob_kzg_commitments = blob_kzg_commitments`.
 
-Note that the `blobs` should be held with the block in preparation of publishing.
-Without the `blobs`, the published block will effectively be ignored by honest validators.
+#### Constructing the `SignedBeaconBlockAndBlobsSidecar`
+To construct a `SignedBeaconBlockAndBlobsSidecar`, a `signed_beacon_block_and_blobs_sidecar` is defined with the necessary context for block and sidecar proposal.
 
-### Beacon Block publishing time
+##### Block
+Set `signed_beacon_block_and_blobs_sidecar.beacon_block = block` where `block` is obtained above.
 
-Before publishing a prepared beacon block proposal, the corresponding blobs are packaged into a sidecar object for distribution to the network:
+##### Sidecar
+Coupled with block, the corresponding blobs are packaged into a sidecar object for distribution to the network.
 
+Set `signed_beacon_block_and_blobs_sidecar.blobs_sidecar = sidecar` where `sidecar` is obtained from:
 ```python
 def get_blobs_sidecar(block: BeaconBlock, blobs: Sequence[Blob]) -> BlobsSidecar:
     return BlobsSidecar(
@@ -235,20 +238,10 @@ def get_blobs_sidecar(block: BeaconBlock, blobs: Sequence[Blob]) -> BlobsSidecar
     )
 ```
 
-And then signed:
+This `signed_beacon_block_and_blobs_sidecar` is then published to the global `beacon_block_and_blobs_sidecar` topic.
 
-```python
-def get_signed_blobs_sidecar(state: BeaconState, blobs_sidecar: BlobsSidecar, privkey: int) -> SignedBlobsSidecar:
-    domain = get_domain(state, DOMAIN_BLOBS_SIDECAR, blobs_sidecar.beacon_block_slot // SLOTS_PER_EPOCH)
-    signing_root = compute_signing_root(blobs_sidecar, domain)
-    signature = bls.Sign(privkey, signing_root)
-    return SignedBlobsSidecar(message=blobs_sidecar, signature=signature)
-```
-
-This `signed_blobs_sidecar` is then published to the global `blobs_sidecar` topic as soon as the `signed_beacon_block` is published.
-
-After publishing the sidecar peers on the network may request the sidecar through sync-requests, or a local user may be interested.
-The validator MUST hold on to blobs for `MIN_EPOCHS_FOR_BLOBS_SIDECARS_REQUESTS` epochs and serve when capable,
+After publishing the peers on the network may request the sidecar through sync-requests, or a local user may be interested.
+The validator MUST hold on to sidecars for `MIN_EPOCHS_FOR_BLOBS_SIDECARS_REQUESTS` epochs and serve when capable,
 to ensure the data-availability of these blobs throughout the network.
 
-After `MIN_EPOCHS_FOR_BLOBS_SIDECARS_REQUESTS` nodes MAY prune the blobs and/or stop serving them.
+After `MIN_EPOCHS_FOR_BLOBS_SIDECARS_REQUESTS` nodes MAY prune the sidecars and/or stop serving them.