diff --git a/da/api/common.py b/da/api/common.py
index 5dbd588..5b7a908 100644
--- a/da/api/common.py
+++ b/da/api/common.py
@@ -3,7 +3,7 @@ from dataclasses import dataclass
 from typing import Optional, List, Sequence
 
 from da.common import BlobId
-from da.verifier import DAShare
+from da.verifier import DABlob
 
 
 @dataclass
diff --git a/da/common.py b/da/common.py
index 1c1804d..9b44f56 100644
--- a/da/common.py
+++ b/da/common.py
@@ -42,33 +42,6 @@ class Bitfield(List[bool]):
     pass
 
 
-@dataclass
-class Attestation:
-    signature: BLSSignature
-
-
-@dataclass
-class Certificate:
-    aggregated_signatures: BLSSignature
-    signers: Bitfield
-    aggregated_column_commitment: Commitment
-    row_commitments: List[Commitment]
-
-    def id(self) -> bytes:
-        return build_blob_id(self.aggregated_column_commitment, self.row_commitments)
-
-    def verify(self, nodes_public_keys: List[BLSPublicKey]) -> bool:
-        """
-        List of nodes public keys should be a trusted list of verified proof of possession keys.
-        Otherwise, we could fall under the Rogue Key Attack
-        `assert all(bls_pop.PopVerify(pk, proof) for pk, proof in zip(node_public_keys, pops))`
-        """
-        # we sort them as the signers bitfield is sorted by the public keys as well
-        signers_keys = list(compress(sorted(nodes_public_keys), self.signers))
-        message = build_blob_id(self.aggregated_column_commitment, self.row_commitments)
-        return NomosDaG2ProofOfPossession.AggregateVerify(signers_keys, [message]*len(signers_keys), self.aggregated_signatures)
-
-
 def build_blob_id(aggregated_column_commitment: Commitment, row_commitments: Sequence[Commitment]) -> BlobId:
     hasher = sha3_256()
     hasher.update(bytes(aggregated_column_commitment))
diff --git a/da/test_full_flow.py b/da/test_full_flow.py
index b463163..7f09fb6 100644
--- a/da/test_full_flow.py
+++ b/da/test_full_flow.py
@@ -2,8 +2,8 @@ from itertools import chain
 from unittest import TestCase
 from typing import List, Optional
 
-from da.common import NodeId, build_blob_id, BLSPublicKey, NomosDaG2ProofOfPossession as bls_pop
-from da.api.common import DAApi, VID, Metadata
+from da.common import NodeId, build_blob_id, NomosDaG2ProofOfPossession as bls_pop
+from da.api.common import DAApi, BlobMetadata, Metadata
 from da.verifier import DAVerifier, DABlob 
 from da.api.test_flow import MockStore
 from da.dispersal import Dispersal, DispersalSettings
@@ -25,7 +25,7 @@ class DAVerifierWApi:
             self.store.populate(blob, cert_id)
             return attestation
 
-    def receive_metadata(self, blob_metadata: BlobMetadata):
+    def receive_metadata(self, vid: BlobMetadata):
         # Usually the certificate would be verifier here,
         # but we are assuming that this it is already coming from the verified block,
         # in which case all certificates had been already verified by the DA Node.
@@ -66,16 +66,16 @@ class TestFullFlow(TestCase):
 
         # inject mock send and await method
         self.dispersal._send_and_await_response = __send_and_await_response
-        self.dispersal.disperse(encoded_data)
-        blob_id = build_blob_id(encoded_data.row_commitments)
-        blob_metadata = BlobMetadata(
-            blob_id,
+        certificate = self.dispersal.disperse(encoded_data)
+
+        vid = BlobMetadata(
+            certificate.id(),
             Metadata(app_id, index)
         )
 
         # verifier
         for node in self.api_nodes:
-            node.receive_metadata(blob_metadata)
+            node.receive_metadata(vid)
 
         # read from api and confirm its working
         # notice that we need to sort the api_nodes by their public key to have the blobs sorted in the same fashion
@@ -109,7 +109,7 @@ class TestFullFlow(TestCase):
         # Loop through each index and simulate dispersal with the same cert_id but different metadata
         for index in indexes:
             metadata = BlobMetadata(
-                blob_id,
+                certificate.id(),
                 Metadata(app_id, index)
             )
 
diff --git a/da/test_verifier.py b/da/test_verifier.py
index e86d42e..2d09eea 100644
--- a/da/test_verifier.py
+++ b/da/test_verifier.py
@@ -22,7 +22,7 @@ class TestVerifier(TestCase):
         aggregated_proof = kzg.generate_element_proof(0, aggregated_poly, GLOBAL_PARAMETERS, ROOTS_OF_UNITY)
         self.assertTrue(
             self.verifier._verify_column(
-                column, column_commitment, aggregated_column_commitment, aggregated_proof, 0
+                column, 0, column_commitment, aggregated_column_commitment, aggregated_proof,
             )
         )
 
@@ -30,9 +30,9 @@ class TestVerifier(TestCase):
         _ = TestEncoder()
         _.setUp()
         encoded_data = _.encoder.encode(_.data)
-        for i, column in enumerate(encoded_data.extended_matrix.columns):
+        for i, column in enumerate(encoded_data.chunked_data.columns):
             verifier = DAVerifier()
-            da_blob = DAShare(
+            da_blob = DABlob(
                 Column(column),
                 i,
                 encoded_data.combined_column_proofs[i],
@@ -60,4 +60,4 @@ class TestVerifier(TestCase):
                 encoded_data.combined_column_proofs[i],
                 encoded_data.row_commitments,
             )
-            self.assertIsNotNone(self.verifier.verify(da_blob))
+            self.assertFalse(self.verifier.verify(da_blob))