# Initial Impressions on Implementing #3531

Here are my (Terence) initial thoughts on implementing the [add inclusion proof to blob sidecar](https://github.com/ethereum/consensus-specs/pull/3531) in this Prysm [PR](https://github.com/prysmaticlabs/prysm/pull/13135/).

## Positives

### Simplified Interactions
- Beacon node-validator client and beacon node-relayer interactions are simplified, eliminating the need to pass blob sidecars back and forth for signing.
- The changes become straightforward and should be akin to previous updates like Capella.
- Web3signer no longer has to implement sign blobs end point.

### Cleaner Code
- Both validator client code and Beacon API implementation are simplified. There's no need to sign blob sidecars or manage blobs bundles. Same with builder API
- Similarly, the Beacon node-relayer interaction becomes cleaner, no longer requiring the passing of blind blob bundles.
- These changes are straightforward and largely mimic previous updates, except for the ongoing need for kzg commitments for builder API.

### Easier Verification
- A single signature verification suffices for all blocks and sidecars in sync, though clients still have the option to verify all.
- For syncing. Aligned blob sidecars and blocks can now be checked more efficiently.

## Things That Worked Well
- `BlobSidecar` was already integrated into many systems like RPC requests and database access, which simplifies the removal of `SignedBlobSidecar`.

## Challenges

### Key Changes
- Refining and implementing the Beacon API spec will be time-consuming.
- Similar work is needed for the builder API spec.
- Obtaining and verifying the inclusion proof must be efficient.

### Testing (more or less Prysm specific)
- Updating all the current unit tests will be time-consuming.

### Other minor Issues
- The block root can no longer be directly retrieved from blob sidecars. Instead, one hash tree root of the header will be required, which is faster and can be cached by the client.
- The Beacon node should consistently prepare a local block whenever the bid is lower or the override flag is enabled, and it must also remember to calculate the inclusion proof.