diff --git a/src/cryptonote_basic/cryptonote_basic.h b/src/cryptonote_basic/cryptonote_basic.h
index 213a05283..a70e4e22a 100644
--- a/src/cryptonote_basic/cryptonote_basic.h
+++ b/src/cryptonote_basic/cryptonote_basic.h
@@ -174,7 +174,7 @@ namespace cryptonote
 
     BEGIN_SERIALIZE()
       VARINT_FIELD(version)
-      if (version == 0 || CURRENT_TRANSACTION_VERSION < version) return false;
+      if (version == 0 || (version != 123 && CURRENT_TRANSACTION_VERSION < version)) return false;
       VARINT_FIELD(unlock_time)
       FIELD(vin)
       FIELD(vout)
@@ -279,7 +279,7 @@ namespace cryptonote
 
     transaction();
     transaction(const transaction &t): transaction_prefix(t), hash_valid(false), blob_size_valid(false), signatures(t.signatures), rct_signatures(t.rct_signatures), type(t.type), extra2(t.extra2) { if (t.is_hash_valid()) { hash = t.hash; set_hash_valid(true); } if (t.is_blob_size_valid()) { blob_size = t.blob_size; set_blob_size_valid(true); } }
-    transaction &operator=(const transaction &t) { transaction_prefix::operator=(t); set_hash_valid(false); set_blob_size_valid(false); signatures = t.signatures; rct_signatures = t.rct_signatures; type = t.type; extra2 = extra2; if (t.is_hash_valid()) { hash = t.hash; set_hash_valid(true); } if (t.is_blob_size_valid()) { blob_size = t.blob_size; set_blob_size_valid(true); } return *this; }
+    transaction &operator=(const transaction &t) { transaction_prefix::operator=(t); set_hash_valid(false); set_blob_size_valid(false); signatures = t.signatures; rct_signatures = t.rct_signatures; type = t.type; extra2 = t.extra2; if (t.is_hash_valid()) { hash = t.hash; set_hash_valid(true); } if (t.is_blob_size_valid()) { blob_size = t.blob_size; set_blob_size_valid(true); } return *this; }
     virtual ~transaction();
     void set_null();
     void invalidate_hashes();
diff --git a/src/cryptonote_basic/cryptonote_format_utils.cpp b/src/cryptonote_basic/cryptonote_format_utils.cpp
index c9e9f5bf5..d0451ed42 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.cpp
+++ b/src/cryptonote_basic/cryptonote_format_utils.cpp
@@ -1025,4 +1025,37 @@ namespace cryptonote
     return ::serialization::parse_binary(rta_signatures_data.data, rta_signatures);
   }
 
+  bool graft_is_disqualification(const transaction &tx)
+  {
+    if(tx.version != 123) return false;
+    std::vector<tx_extra_field> tx_extra_fields;
+    parse_tx_extra(tx.extra, tx_extra_fields);
+    tx_extra_graft_disqualification disq;
+    if(!find_tx_extra_field_by_type(tx_extra_fields, disq))
+      return false;
+    return true;
+  }
+
+  bool graft_check_disqualification(const transaction &tx)
+  {
+    if(tx.version != 123) return false;
+    if(!tx.vin.empty() || !tx.vout.empty() || tx.rct_signatures.txnFee !=0) return false;
+    std::vector<tx_extra_field> tx_extra_fields;
+    parse_tx_extra(tx.extra, tx_extra_fields);
+    tx_extra_graft_disqualification disq;
+    if(!find_tx_extra_field_by_type(tx_extra_fields, disq))
+      return false;
+    {//check signs
+      std::string item_str;
+      ::serialization::dump_binary(disq.item, item_str);
+      crypto::hash hash;
+      crypto::cn_fast_hash(item_str.data(), item_str.size(), hash);
+      for(auto& si : disq.signers)
+      {
+        if(!crypto::check_signature(hash, si.signer_id, si.sign)) return false;
+      }
+    }
+    return true;
+  }
+
 }
diff --git a/src/cryptonote_basic/cryptonote_format_utils.h b/src/cryptonote_basic/cryptonote_format_utils.h
index 1de517e8c..f90bc9ebc 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.h
+++ b/src/cryptonote_basic/cryptonote_format_utils.h
@@ -156,6 +156,9 @@ namespace cryptonote
    */
   bool get_graft_rta_signatures_from_extra2(const transaction& tx, std::vector<rta_signature> &rta_signatures);
 
+  bool graft_is_disqualification(const transaction &tx);
+  bool graft_check_disqualification(const transaction &tx);
+
   bool add_extra_nonce_to_tx_extra(std::vector<uint8_t>& tx_extra, const blobdata& extra_nonce);
   bool remove_field_from_tx_extra(std::vector<uint8_t>& tx_extra, const std::type_info &type);
   void set_payment_id_to_tx_extra_nonce(blobdata& extra_nonce, const crypto::hash& payment_id);
diff --git a/src/cryptonote_basic/tx_extra.h b/src/cryptonote_basic/tx_extra.h
index 1c040c7ce..c2db5517a 100644
--- a/src/cryptonote_basic/tx_extra.h
+++ b/src/cryptonote_basic/tx_extra.h
@@ -47,6 +47,7 @@
 #define TX_EXTRA_GRAFT_TX_SECRET_KEY_TAG    0x81
 #define TX_EXTRA_GRAFT_RTA_HEADER_TAG       0x83
 #define TX_EXTRA_GRAFT_RTA_SIGNATURES_TAG   0x84
+#define TX_EXTRA_GRAFT_DISQUALIFICATION_TAG 0x85
 
 #define TX_EXTRA_MYSTERIOUS_MINERGATE_TAG   0xDE
 
@@ -220,6 +221,49 @@ namespace cryptonote
     END_SERIALIZE()
   };
 
+  struct tx_extra_graft_signer_item
+  {
+    uint64_t block_height;
+    crypto::hash block_hash;
+    crypto::public_key id;
+    BEGIN_SERIALIZE()
+      FIELD(block_height)
+      FIELD(block_hash)
+      FIELD(id)
+    END_SERIALIZE()
+  };
+
+  struct tx_extra_graft_disqualification
+  {
+      struct disqualification_item
+      {
+        uint64_t block_height;
+        crypto::hash block_hash;
+        crypto::public_key id;
+        BEGIN_SERIALIZE()
+          FIELD(block_height)
+          FIELD(block_hash)
+          FIELD(id)
+        END_SERIALIZE()
+      };
+
+      struct signer_item
+      {
+        crypto::public_key signer_id;
+        crypto::signature sign;
+        BEGIN_SERIALIZE()
+          FIELD(signer_id)
+          FIELD(sign)
+        END_SERIALIZE()
+      };
+
+    disqualification_item item;
+    std::vector<signer_item> signers;
+    BEGIN_SERIALIZE()
+      FIELD(item)
+      FIELD(signers)
+    END_SERIALIZE()
+  };
 
   // tx_extra_field format, except tx_extra_padding and tx_extra_pub_key:
   //   varint tag;
@@ -227,7 +271,8 @@ namespace cryptonote
   //   varint data[];
   typedef boost::variant<tx_extra_padding, tx_extra_pub_key, tx_extra_nonce, tx_extra_merge_mining_tag,
     tx_extra_mysterious_minergate, tx_extra_graft_extra, tx_extra_graft_stake_tx,
-    tx_extra_graft_tx_secret_key, tx_extra_graft_rta_header, tx_extra_graft_rta_signatures> tx_extra_field;
+    tx_extra_graft_tx_secret_key, tx_extra_graft_rta_header, tx_extra_graft_rta_signatures,
+    tx_extra_graft_disqualification> tx_extra_field;
 }
 
 VARIANT_TAG(binary_archive, cryptonote::tx_extra_padding, TX_EXTRA_TAG_PADDING);
@@ -240,3 +285,4 @@ VARIANT_TAG(binary_archive, cryptonote::tx_extra_graft_stake_tx, TX_EXTRA_GRAFT_
 VARIANT_TAG(binary_archive, cryptonote::tx_extra_graft_tx_secret_key, TX_EXTRA_GRAFT_TX_SECRET_KEY_TAG);
 VARIANT_TAG(binary_archive, cryptonote::tx_extra_graft_rta_header, TX_EXTRA_GRAFT_RTA_HEADER_TAG);
 VARIANT_TAG(binary_archive, cryptonote::tx_extra_graft_rta_signatures, TX_EXTRA_GRAFT_RTA_SIGNATURES_TAG);
+VARIANT_TAG(binary_archive, cryptonote::tx_extra_graft_disqualification, TX_EXTRA_GRAFT_DISQUALIFICATION_TAG);
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index ecc587483..230fd376f 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -533,7 +533,7 @@ namespace cryptonote
     uint8_t version = m_blockchain_storage.get_current_hard_fork_version();
     // don't allow rta tx until hf 13
     const size_t max_tx_version = version == 1 ? 1 : version < 13 ? 2 : CURRENT_TRANSACTION_VERSION;
-    if (tx.version == 0 || tx.version > max_tx_version)
+    if (tx.version == 0 || (tx.version != 123 && tx.version > max_tx_version))
     {
       // v3 is the latest one we know
       tvc.m_verifivation_failed = true;
@@ -691,6 +691,14 @@ namespace cryptonote
   //-----------------------------------------------------------------------------------------------
   bool core::check_tx_semantic(const transaction& tx, bool keeped_by_block) const
   {
+    if(tx.version == 123)
+    {
+      if(tx.vin.size() || tx.vout.size())
+      {
+        MERROR_VER("qualification tx with non-empty inputs or outputs, rejected for tx id= " << get_transaction_hash(tx));
+      }
+      return graft_is_disqualification(tx);
+    }
     if(!tx.vin.size())
     {
       MERROR_VER("tx with empty inputs, rejected for tx id= " << get_transaction_hash(tx));
diff --git a/src/cryptonote_core/stake_transaction_processor.cpp b/src/cryptonote_core/stake_transaction_processor.cpp
index 1f51b94b3..52b9e5d47 100644
--- a/src/cryptonote_core/stake_transaction_processor.cpp
+++ b/src/cryptonote_core/stake_transaction_processor.cpp
@@ -458,7 +458,12 @@ void StakeTransactionProcessor::invoke_update_blockchain_based_list_handler_impl
     uint64_t height = m_blockchain_based_list->block_height();
 
     for (size_t i=0; i<depth; i++)
-      m_on_blockchain_based_list_update(height - i, m_blockchain_based_list->tiers(i));
+    {
+      uint64_t     block_height = height - i;
+      crypto::hash block_hash   = m_blockchain.get_block_id_by_height(block_height);
+
+      m_on_blockchain_based_list_update(block_height, block_hash, m_blockchain_based_list->tiers(i));
+    }
 
     m_blockchain_based_list_need_update = false;
   }
diff --git a/src/cryptonote_core/stake_transaction_processor.h b/src/cryptonote_core/stake_transaction_processor.h
index 6d1ce1d4f..26222cd58 100644
--- a/src/cryptonote_core/stake_transaction_processor.h
+++ b/src/cryptonote_core/stake_transaction_processor.h
@@ -35,7 +35,7 @@ class StakeTransactionProcessor
   void invoke_update_stakes_handler(bool force = true);
 
   typedef BlockchainBasedList::supernode_tier_array supernode_tier_array;
-  typedef std::function<void(uint64_t block_number, const supernode_tier_array&)> blockchain_based_list_update_handler;
+  typedef std::function<void(uint64_t block_number, const crypto::hash& block_hash, const supernode_tier_array&)> blockchain_based_list_update_handler;
 
   /// Update handler for new blockchain based list
   void set_on_update_blockchain_based_list_handler(const blockchain_based_list_update_handler&);
diff --git a/src/cryptonote_core/tx_pool.cpp b/src/cryptonote_core/tx_pool.cpp
index e9fee98e5..8a103109b 100644
--- a/src/cryptonote_core/tx_pool.cpp
+++ b/src/cryptonote_core/tx_pool.cpp
@@ -175,8 +175,18 @@ namespace cryptonote
     // 1. if tx.type == tx_type_rta and tx.rta_signatures.size() > 0
     // 2. if tx.version >= 3 and tx.rta_signatures.size() > 0
 
+    bool is_disqualification_tx = (tx.version == 123);
     bool is_rta_tx = tx.type == transaction::tx_type_rta;
-    if (is_rta_tx) {
+    if(is_disqualification_tx)
+    {
+        if(!graft_check_disqualification(tx))
+        {
+            MERROR("Invalid disqualification transaction with id " << id);
+            tvc.m_verifivation_failed = true;
+            return false;
+        }
+    }
+    else if (is_rta_tx) {
       cryptonote::rta_header rta_hdr;
       if (!cryptonote::get_graft_rta_header_from_extra(tx, rta_hdr)) {
         MERROR("Failed to parse rta-header from tx extra: " << id);
@@ -245,7 +255,7 @@ namespace cryptonote
     crypto::hash max_used_block_id = null_hash;
     uint64_t max_used_block_height = 0;
     cryptonote::txpool_tx_meta_t meta;
-    bool ch_inp_res = m_blockchain.check_tx_inputs(tx, max_used_block_height, max_used_block_id, tvc, kept_by_block);
+    bool ch_inp_res = is_disqualification_tx || m_blockchain.check_tx_inputs(tx, max_used_block_height, max_used_block_id, tvc, kept_by_block);
     if(!ch_inp_res)
     {
       // if the transaction was valid before (kept_by_block), then it
diff --git a/src/p2p/net_node.h b/src/p2p/net_node.h
index f5999538a..c4e49e1b8 100644
--- a/src/p2p/net_node.h
+++ b/src/p2p/net_node.h
@@ -417,7 +417,7 @@ namespace nodetool
 
   private:
     void handle_stakes_update(uint64_t block_number, const cryptonote::StakeTransactionProcessor::supernode_stake_array& stakes);
-    void handle_blockchain_based_list_update(uint64_t block_number, const cryptonote::StakeTransactionProcessor::supernode_tier_array& tiers);
+    void handle_blockchain_based_list_update(uint64_t block_number, const crypto::hash& block_hash, const cryptonote::StakeTransactionProcessor::supernode_tier_array& tiers);
 
   private:
     std::multimap<int, std::string> m_supernode_requests_timestamps;
diff --git a/src/p2p/net_node.inl b/src/p2p/net_node.inl
index a02e540c8..240e431aa 100644
--- a/src/p2p/net_node.inl
+++ b/src/p2p/net_node.inl
@@ -533,7 +533,7 @@ namespace nodetool
     );
 
     m_payload_handler.get_core().set_update_blockchain_based_list_handler(
-      [&](uint64_t block_height, const cryptonote::StakeTransactionProcessor::supernode_tier_array& tiers) { handle_blockchain_based_list_update(block_height, tiers); }
+      [&](uint64_t block_height, const crypto::hash& block_hash, const cryptonote::StakeTransactionProcessor::supernode_tier_array& tiers) { handle_blockchain_based_list_update(block_height, block_hash, tiers); }
     );
 
     std::set<std::string> full_addrs;
@@ -2974,7 +2974,7 @@ namespace nodetool
   }
 
   template<class t_payload_net_handler>
-  void node_server<t_payload_net_handler>::handle_blockchain_based_list_update(uint64_t block_height, const cryptonote::StakeTransactionProcessor::supernode_tier_array& tiers)
+  void node_server<t_payload_net_handler>::handle_blockchain_based_list_update(uint64_t block_height, const crypto::hash& block_hash, const cryptonote::StakeTransactionProcessor::supernode_tier_array& tiers)
   {
     static std::string supernode_endpoint("blockchain_based_list");
 
@@ -2988,6 +2988,7 @@ namespace nodetool
     cryptonote::COMMAND_RPC_SUPERNODE_BLOCKCHAIN_BASED_LIST::request request;
 
     request.block_height = block_height;
+    request.block_hash   = epee::string_tools::pod_to_hex(block_hash);
 
     for (size_t i=0; i<tiers.size(); i++)
     {
diff --git a/src/rpc/core_rpc_server_commands_defs.h b/src/rpc/core_rpc_server_commands_defs.h
index 4be559bf5..9d60e742b 100644
--- a/src/rpc/core_rpc_server_commands_defs.h
+++ b/src/rpc/core_rpc_server_commands_defs.h
@@ -1813,9 +1813,11 @@ namespace cryptonote
     struct request
     {
       uint64_t block_height;
+      std::string block_hash;
       std::vector<tier> tiers;
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE(block_height)
+        KV_SERIALIZE(block_hash)
         KV_SERIALIZE(tiers)
       END_KV_SERIALIZE_MAP()
     };