- _[IGNORE]_ The `bid` is published 1 slot early or later (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) --
i.e. validate that `bid.slot <= current_slot + 1`
(a client MAY queue future samples for propagation at the appropriate slot).
- _[IGNORE]_ The `bid` is for the current or next block
i.e. validate that `bid.slot >= current_slot`
- _[IGNORE]_ The `bid` is the first `bid` valid bid for `bid.slot`, or the bid is at least 1% higher than the previous known `bid`
- _[REJECT]_ The validator defined by `bid.validator_index` exists and is slashable.
- _[REJECT]_ The bid signature, which is an Eth1 signature, needs to be valid and the address needs to contain enough Ether to cover the bid and the data gas base fee.
#### Shard sample subnets
Shard sample (row/column) subnets are used by builders to make their samples available as part of their intermediate block release after selection by beacon block proposers.
##### `shard_row_{subnet_id}`
Shard sample data, in the form of a `SignedShardSample` is published to the `shard_row_{subnet_id}` and `shard_column_{subnet_id}` subnets.
The following validations MUST pass before forwarding the `sample`.
- _[IGNORE]_ The `sample` is published 1 slot early or later (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) --
i.e. validate that `sample.slot <= current_slot + 1`
(a client MAY queue future samples for propagation at the appropriate slot).
- _[IGNORE]_ The `sample` is new enough to still be processed --
i.e. validate that `compute_epoch_at_slot(sample.slot) >= get_previous_epoch(state)`
- _[REJECT]_ The shard sample is for the correct subnet --
i.e. `sample.row == subnet_id` for `shard_row_{subnet_id}` and `sample.column == subnet_id` for `shard_column_{subnet_id}`
- _[IGNORE]_ The sample is the first sample with valid signature received for the `(sample.builder, sample.slot, sample.row, sample.column)` combination.
- _[REJECT]_ The `sample.data` MUST NOT contain any point `x >= BLS_MODULUS`. Although it is a `uint256`, not the full 256 bit range is valid.
- _[REJECT]_ The validator defined by `sample.builder` exists and is slashable.
- _[REJECT]_ The sample is proposed by the expected `builder` for the sample's `slot`.
i.e., the beacon block at `sample.slot - 1` according to the node's fork choice contains an `IntermediateBlockBid`
with `intermediate_block_bid.validator_index == sample.builder`
- _[REJECT]_ The sample signature, `sample.signature`, is valid for the builder --
i.e. `bls.Verify(builder_pubkey, sample_signing_root, sample.signature)` OR `sample.signature == Bytes96(b"\0" * 96)` AND
