diff --git a/e-voting-system/backend/blockchain_client.py b/e-voting-system/backend/blockchain_client.py
index b59acb1..6e50701 100644
--- a/e-voting-system/backend/blockchain_client.py
+++ b/e-voting-system/backend/blockchain_client.py
@@ -153,7 +153,8 @@ class BlockchainClient:
         voter_id: str,
         election_id: int,
         encrypted_vote: str,
-        transaction_id: Optional[str] = None
+        transaction_id: Optional[str] = None,
+        ballot_hash: Optional[str] = None
     ) -> Dict[str, Any]:
         """
         Submit a vote to the PoA blockchain network.
@@ -161,8 +162,9 @@ class BlockchainClient:
         Args:
             voter_id: Voter identifier
             election_id: Election ID
-            encrypted_vote: Encrypted vote (base64 or hex)
+            encrypted_vote: Encrypted vote data
             transaction_id: Optional transaction ID (generated if not provided)
+            ballot_hash: Optional ballot hash for verification
 
         Returns:
             Transaction receipt with block hash and index
@@ -179,6 +181,27 @@ class BlockchainClient:
             import uuid
             transaction_id = f"tx-{uuid.uuid4().hex[:12]}"
 
+        # Generate ballot hash if not provided
+        if not ballot_hash:
+            import hashlib
+            ballot_hash = hashlib.sha256(f"{voter_id}{election_id}{encrypted_vote}".encode()).hexdigest()
+
+        import time
+
+        # Create transaction data as JSON
+        tx_data = {
+            "voter_id": str(voter_id),
+            "election_id": int(election_id),
+            "encrypted_vote": str(encrypted_vote),
+            "ballot_hash": str(ballot_hash),
+            "timestamp": int(time.time())
+        }
+
+        # Encode transaction data as hex string with 0x prefix
+        import json
+        tx_json = json.dumps(tx_data)
+        data_hex = "0x" + tx_json.encode().hex()
+
         # Prepare JSON-RPC request
         rpc_request = {
             "jsonrpc": "2.0",
@@ -186,7 +209,7 @@ class BlockchainClient:
             "params": [{
                 "from": voter_id,
                 "to": f"election-{election_id}",
-                "data": encrypted_vote,
+                "data": data_hex,
                 "gas": "0x5208"
             }],
             "id": transaction_id
diff --git a/e-voting-system/backend/routes/votes.py b/e-voting-system/backend/routes/votes.py
index a9e7bf7..a00bb8c 100644
--- a/e-voting-system/backend/routes/votes.py
+++ b/e-voting-system/backend/routes/votes.py
@@ -130,7 +130,8 @@ async def submit_simple_vote(
             submission_result = await poa_client.submit_vote(
                 voter_id=current_voter.id,
                 election_id=election_id,
-                encrypted_vote=ballot_hash,  # Use ballot hash as data
+                encrypted_vote="",  # Empty for MVP (not encrypted)
+                ballot_hash=ballot_hash,
                 transaction_id=transaction_id
             )
             blockchain_response = {
@@ -272,6 +273,7 @@ async def submit_vote(
                 voter_id=current_voter.id,
                 election_id=vote_bulletin.election_id,
                 encrypted_vote=vote_bulletin.encrypted_vote,
+                ballot_hash=ballot_hash,
                 transaction_id=transaction_id
             )