diff --git a/BlockChain/Chain.py b/BlockChain/Chain.py
index fcd48b2..434cb13 100644
--- a/BlockChain/Chain.py
+++ b/BlockChain/Chain.py
@@ -49,6 +49,7 @@ def __init__(self):
     def sync_chain(self, current_chain):
         self.chain = current_chain.chain
         self.pendingTransactions = current_chain.pendingTransactions
+        self.account_model = current_chain.account_model
 
     def genesis(self):
         block_to_add = Block(
@@ -71,21 +72,6 @@ def get_wallet_data(self, wallet_address):
     def get_last_hash(self):
         return Utils.hash(self._last_block.payload()).hexdigest()
 
-    # def new_block(self, block):
-    #     self.next_block_chooser.scan_block(block)
-
-    """
-    # check that the signature corresponds to transaction
-    # signed by the public key (sender_address)
-    def addBlock(self, senderKey, signature, transaction):
-        publicKey = RSA.importKey(binascii.unhexlify(senderKey))
-        verifier = PKCS1_v1_5.new(publicKey)
-        _hash = SHA.new(transaction.toString().encode('utf8'))
-
-        if verifier.verify(_hash, binascii.unhexlify(signature)):
-            self.pendingTransactions.append(transaction)
-    """
-
     def insert_transaction(self, transaction: Transaction):
         # check transaction signature
         signature_valid = self.transaction_validation(transaction)
@@ -94,11 +80,6 @@ def insert_transaction(self, transaction: Transaction):
 
         if signature_valid and transaction_exists:
             self.pendingTransactions.append(transaction)
-        else:
-            print()
-            raise TransactionValidationError(
-                "Transaction signature not valid or already existing !"
-            )
 
     def remove_transactions(self, transactions):
         for transaction in transactions:
@@ -192,7 +173,7 @@ def check_transaction(self, transaction):
                 return False
         return True
 
-    def check_block_transaction(self, transaction):
+    def check_block_transaction(self, transaction: Transaction):
         for block in self.chain:
             for curr_transaction in block.get_transactions():
                 if curr_transaction.equals(transaction):
@@ -267,6 +248,11 @@ def transaction_validation(self, transaction):
 
         return True
 
+    def check_block_count(self, block: Block):
+        if self.chain[-1].get_index() == block.get_index() - 1:
+            return True
+        return False
+
     def last_index(self):
         return self._last_block.get_index()
 
diff --git a/BlockChain/Node.py b/BlockChain/Node.py
index 02b8852..5959fd8 100644
--- a/BlockChain/Node.py
+++ b/BlockChain/Node.py
@@ -1,3 +1,4 @@
+from email import message
 from quopri import encodestring
 from Chain import Chain
 from Wallet.Wallet import Wallet
@@ -49,17 +50,24 @@ def handle_transaction(self, transaction):
                 self.forge_block()
 
     def handle_block(self, block: Block):
-        signature_valid = Wallet.check_verified(
-            block.payload(), block.get_signature(), block.get_forger()
-        )
-        if signature_valid:
-            self.blockchain.push_block(block)
+        # signature_valid = Wallet.check_verified(
+        #     block.payload(), block.get_signature(), block.get_forger()
+        # )
+        # if signature_valid:
 
-            message = Message(self.p2p.socketConnector, "BLOCK", block)
-            # Encode the message
-            message_encoded = Utils.encode(message)
-            # Broadcast the encoded message
-            self.p2p.broadcast(message_encoded)
+        # check of a a blockchain is in sync with the network
+        # if not, update the blocks
+        if not self.blockchain.check_block_count(block):
+            print("BLOCKCHAIN REQUEST")
+            self.request_chain()
+
+        self.blockchain.push_block(block)
+
+        message = Message(self.p2p.socketConnector, "BLOCK", block)
+        # Encode the message
+        message_encoded = Utils.encode(message)
+        # Broadcast the encoded message
+        self.p2p.broadcast(message_encoded)
 
     # notifies the blockchain that is time to forge a new block
     def forge_block(self):
@@ -72,6 +80,22 @@ def forge_block(self):
             encoded_message = Utils.encode(message)
             self.p2p.broadcast(encoded_message)
 
+    # request the blockchain from other nodes
+    def request_chain(self):
+        message = Message(self.p2p.socketConnector, "BLOCKCHAINREQUEST", None)
+        encoded_message = Utils.encode(message)
+        self.p2p.broadcast(encoded_message)
+
+    # send blockchain data to a certain node
+    def handle_chain_request(self, request_node):
+        message = Message(self.p2p.socketConnector, "BLOCKCHAIN", self.blockchain)
+        encoded_message = Utils.encode(message)
+        self.p2p.send(request_node, encoded_message)
+
+    # update current blockchain from fetched one
+    def handle_received_blockchain(self, blockchain):
+        self.blockchain.sync_chain(blockchain)
+
     def startP2P(self):
         self.p2p = SocketCommunication(self.ip, self.port)
         self.p2p.startSocketCommunication(self)
diff --git a/BlockChain/P2P/SocketCommunication.py b/BlockChain/P2P/SocketCommunication.py
index bf6822c..245abd5 100644
--- a/BlockChain/P2P/SocketCommunication.py
+++ b/BlockChain/P2P/SocketCommunication.py
@@ -42,6 +42,11 @@ def node_message(self, node, data):
         elif message.message_type == "BLOCK":
             block = message.data
             self.node.handle_block(block)
+        elif message.message_type == "BLOCKCHAINREQUEST":
+            self.node.handle_chain_request(node)
+        elif message.message_type == "BLOCKCHAIN":
+            blockchain = message.data
+            self.node.handle_received_blockchain(blockchain)
 
     def send(self, receiver, data):
         self.send_to_node(receiver, data)
diff --git a/BlockChain/Trans_api.py b/BlockChain/Trans_api.py
index 583bac2..831faeb 100644
--- a/BlockChain/Trans_api.py
+++ b/BlockChain/Trans_api.py
@@ -33,6 +33,6 @@ def postTransaction(sender, receiver, amount, type):
     postTransaction(exchange, wallet1, 100, "EXCHANGE")
     postTransaction(exchange, wallet1, 10, "EXCHANGE")
 
-    # postTransaction(wallet1, wallet1, 25, "STAKE")
-    # postTransaction(wallet2, wallet1, 1, "TRANSFER")
-    # postTransaction(wallet2, wallet1, 1, "TRANSFER")
+    postTransaction(wallet1, wallet1, 25, "STAKE")
+    postTransaction(wallet2, wallet1, 10, "TRANSFER")
+    postTransaction(wallet2, wallet1, 10, "TRANSFER")