diff --git a/src/connectivity_tool/conn_tool.cpp b/src/connectivity_tool/conn_tool.cpp
index 031b248d..ff88563a 100644
--- a/src/connectivity_tool/conn_tool.cpp
+++ b/src/connectivity_tool/conn_tool.cpp
@@ -104,6 +104,7 @@ struct response_schema
           "\"time_started\": "  << ce.time_started << ", "
           "\"last_recv\": "     << ce.last_recv << ", "
           "\"last_send\": "     << ce.last_send << ", "
+          "\"version\": "       << ce.version << ", "
           "\"is_income\": "     << ce.is_income << "}";
         if(rs.ns_rsp.v.connections_list.size()-1 != i)
           ss << ",";
diff --git a/src/crypto/wild_keccak.cpp b/src/crypto/wild_keccak.cpp
index c2f03929..d4986a8c 100644
--- a/src/crypto/wild_keccak.cpp
+++ b/src/crypto/wild_keccak.cpp
@@ -116,20 +116,20 @@ namespace crypto
       st[0] ^= keccakf_rndc[round];
     }
   }
+  bool generate_scratchpad(const std::vector<crypto::hash>& seed_data, std::vector<crypto::hash>& result_data, uint64_t target_size)
+  {
+    //this is very basic implementation, not considered for production (possible to reduce memory by keeping only every x10 item and calc it instead of read)
+    //TODO: research safe way for scratchpad generation
+    if (target_size == 0 || seed_data.size() == 0)
+      return false;
+    result_data.resize(target_size);
+    result_data[0] = crypto::cn_fast_hash(&seed_data[0], sizeof(seed_data[0]) * seed_data.size());
+    //crypto::hash = get_transaction_hash()
+    for (size_t i = 1; i < target_size; i++)
+    {
+      result_data[i] = crypto::cn_fast_hash(&result_data[i - 1], sizeof(result_data[i - 1]));
+    }
+    return true;
+  }
 }
 
-bool generate_scratchpad(const std::vector<crypto::hash>& seed_data, std::vector<crypto::hash>& result_data, uint64_t target_size)
-{
-  //this is very basic implementation, not considered for production (possible to reduce memory by keeping only every x10 item and calc it instead of read)
-  //TODO: research safe way for scratchpad generation
-  if (target_size == 0 || seed_data.size() == 0)
-    return false;
-  result_data.resize(target_size);
-  result_data[0] = crypto::cn_fast_hash(&seed_data[0], sizeof(seed_data[0]) * seed_data.size());
-  //crypto::hash = get_transaction_hash()
-  for (size_t i = 1; i < target_size; i++)
-  {
-    result_data[i] = crypto::cn_fast_hash(&result_data[i-1], sizeof(result_data[i - 1]));
-  }
-  return true;
-}
\ No newline at end of file
diff --git a/src/currency_core/blockchain_storage.cpp b/src/currency_core/blockchain_storage.cpp
index 42840ab4..fa26fd99 100644
--- a/src/currency_core/blockchain_storage.cpp
+++ b/src/currency_core/blockchain_storage.cpp
@@ -264,7 +264,6 @@ bool blockchain_storage::init(const std::string& config_folder, const boost::pro
     if (m_db_storage_minor_compatibility_version < 1)
       need_reinit_medians = true;
   }
-
   if (need_reinit)
   {
     clear();
@@ -4226,9 +4225,8 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
       << "expected: " << get_top_block_id());
     return false;
   }
-#ifdef _DEBUG
+
   uint64_t h = get_block_height(bl);
-#endif// _DEBUG
 
   if(!check_block_timestamp_main(bl))
   {
@@ -4273,7 +4271,12 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
   }
   else
   {
-    proof_hash = get_block_longhash(bl);
+    //++++++++++++++++++++++++++++++++++++++++++++++++++++++
+    //precaution(do we really need this check?)
+    check_scratchpad();
+    //++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+    proof_hash = m_scratchpad.get_pow_hash(bl);
 
     if (!check_hash(proof_hash, current_diffic))
     {
@@ -4541,23 +4544,29 @@ void blockchain_storage::on_block_added(const block_extended_info& bei, const cr
 {
   update_next_comulative_size_limit();
   m_timestamps_median_cache.clear();
-  if (get_scratchpad_size_by_height(bei.height) != m_scratchpad.size())
-  {
-    std::vector<crypto::hash> seed;
-
-    m_scratchpad.update(bei.height);
-  }
-
+  check_scratchpad();
   m_tx_pool.on_blockchain_inc(bei.height, id);
   TIME_MEASURE_START_PD(raise_block_core_event);
   rise_core_event(CORE_EVENT_BLOCK_ADDED, void_struct());
   TIME_MEASURE_FINISH_PD(raise_block_core_event);
 }
 //------------------------------------------------------------------
+bool blockchain_storage::check_scratchpad()
+{
+  if (get_scratchpad_size_for_height(m_db_blocks.size()) != m_scratchpad.size())
+  {
+    std::vector<crypto::hash> seed;
+    get_seed_for_scratchpad(m_db_blocks.size(), seed);
+    m_scratchpad.update(seed, m_db_blocks.size());
+  }
+  return true;
+}
+//------------------------------------------------------------------
 void blockchain_storage::on_block_removed(const block_extended_info& bei)
 {
   m_tx_pool.on_blockchain_dec(m_db_blocks.size() - 1, get_top_block_id());
   m_timestamps_median_cache.clear();
+  check_scratchpad();
   LOG_PRINT_L2("block at height " << bei.height << " was removed from the blockchain");
 }
 //------------------------------------------------------------------
@@ -5296,7 +5305,31 @@ bool blockchain_storage::get_seed_for_scratchpad(uint64_t height, std::vector<cr
   CRITICAL_REGION_LOCAL(m_read_lock);
   CHECK_AND_ASSERT_THROW_MES(m_db_blocks.size() > height, "Internal error: m_db_blocks.size()=" << m_db_blocks.size() << " > height=" << height);
   uint64_t last_upd_h = get_scratchpad_last_update_rebuild_height(height);
+  if (last_upd_h == 0)
+  {
+    crypto::hash genesis_seed = null_hash;
+    bool r = epee::string_tools::hex_to_pod(CURRENCY_SCRATCHPAD_GENESIS_SEED, genesis_seed);
+    CHECK_AND_ASSERT_THROW_MES(r, "Unable to parse CURRENCY_SCRATCHPAD_GENESIS_SEED " << CURRENCY_SCRATCHPAD_GENESIS_SEED);
+    LOG_PRINT_MAGENTA("[SCRATCHPAD] GENESIS SEED SELECTED: " << genesis_seed, LOG_LEVEL_1);
+    seed.push_back(genesis_seed);
+    return true;
+  }
+  uint64_t low_bound_window = 0;
+  CHECK_AND_ASSERT_THROW_MES(last_upd_h >= CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW, "Internal error: last_upd_h(" << last_upd_h <<") < CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW(" << CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW << ")");
+  low_bound_window = last_upd_h - CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW;
 
+  crypto::hash selector_id = get_block_hash(m_db_blocks[last_upd_h - CURRENCY_SCRATCHPAD_BASE_INDEX_ID_OFFSET]->bl);
+
+  const uint64_t* pselectors = (const uint64_t*)&selector_id;
+  std::stringstream ss;
+  for (size_t i = 0; i != 4; i++)
+  {
+    seed.push_back(get_block_hash(m_db_blocks[low_bound_window + pselectors[i] % CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW]->bl));
+    ss << "[" << std::setw(8) << std::hex << pselectors[i] << "->" << low_bound_window + pselectors[i] % CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW << "]"<<seed.back() << ENDL;
+  }
+  LOG_PRINT_MAGENTA("[SCRATCHPAD] SEED SELECTED: h = " << last_upd_h << ", selector: " << selector_id << ENDL << ss.str(), LOG_LEVEL_1);
+
+  return true;
 }
 //------------------------------------------------------------------
 bool blockchain_storage::get_transaction_from_pool_or_db(const crypto::hash& tx_id, std::shared_ptr<transaction>& tx_ptr, uint64_t min_allowed_block_height /* = 0 */) const
diff --git a/src/currency_core/blockchain_storage.h b/src/currency_core/blockchain_storage.h
index aa0e39e9..c233e9f7 100644
--- a/src/currency_core/blockchain_storage.h
+++ b/src/currency_core/blockchain_storage.h
@@ -538,6 +538,7 @@ namespace currency
     bool update_alt_out_indexes_for_tx_in_block(const transaction& tx, alt_block_extended_info& abei)const;
     bool get_transaction_from_pool_or_db(const crypto::hash& tx_id, std::shared_ptr<transaction>& tx_ptr, uint64_t min_allowed_block_height = 0) const;
     bool get_seed_for_scratchpad(uint64_t height, std::vector<crypto::hash>& seed);
+    bool check_scratchpad();
 
     bool prevalidate_miner_transaction(const block& b, uint64_t height, bool pos)const;
     bool validate_transaction(const block& b, uint64_t height, const transaction& tx)const;
diff --git a/src/currency_core/connection_context.h b/src/currency_core/connection_context.h
index 27c54cf7..6c242cc1 100644
--- a/src/currency_core/connection_context.h
+++ b/src/currency_core/connection_context.h
@@ -32,7 +32,6 @@ namespace currency
     //members that supposed to be accessed only from one thread
     std::list<block_context_info> m_needed_objects;
     std::unordered_set<crypto::hash> m_requested_objects;
-    std::string m_remote_version;
     std::atomic<uint32_t> m_callback_request_count; //in debug purpose: problem with double callback rise
 
   };
@@ -51,6 +50,7 @@ namespace currency
     uint64_t m_remote_blockchain_height;
     uint64_t m_last_response_height;
     int64_t m_time_delta;
+    std::string m_remote_version;
   private:
     template<class t_core> friend class t_currency_protocol_handler;
     uncopybale_currency_context m_priv;
diff --git a/src/currency_core/currency_config.h b/src/currency_core/currency_config.h
index 1acf67e4..62dadb3f 100644
--- a/src/currency_core/currency_config.h
+++ b/src/currency_core/currency_config.h
@@ -47,8 +47,12 @@
 #define BASE_REWARD_DUST_THRESHOLD                      ((uint64_t)1000000) // pow(10, 6) - change this will cause hard-fork!
 #define DEFAULT_DUST_THRESHOLD                          ((uint64_t)0)//((uint64_t)100000) // pow(10, 5)
 
-#define CURRENCY_SCRATCHPAD_BASE_SIZE                   16777216 //count in crypto::hash, to get size in bytes x32
+//#define CURRENCY_SCRATCHPAD_BASE_SIZE                   16777216 //count in crypto::hash, to get size in bytes x32
+#define CURRENCY_SCRATCHPAD_BASE_SIZE                   167 //count in crypto::hash, to get size in bytes x32
 #define CURRENCY_SCRATCHPAD_REBUILD_INTERVAL            720 //once a day if block goes once in 2 minute
+#define CURRENCY_SCRATCHPAD_BASE_INDEX_ID_OFFSET        20  //offset down from last rebuild height to block id, that used for indexing seed blocks in CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW
+#define CURRENCY_SCRATCHPAD_SEED_BLOCKS_WINDOW          700 //window for addressing seed block ids 
+#define CURRENCY_SCRATCHPAD_GENESIS_SEED                "4c98962ddce32c7763bb9326933a4692975ca29a76349ae7a139faa3430cc5ab"
 
 #define TX_DEFAULT_FEE                                  ((uint64_t)100000) // pow(10, 5)
 #define TX_MINIMUM_FEE                                  ((uint64_t)100000) // pow(10, 5)
diff --git a/src/currency_core/currency_format_utils.cpp b/src/currency_core/currency_format_utils.cpp
index 8958c55a..7d370140 100644
--- a/src/currency_core/currency_format_utils.cpp
+++ b/src/currency_core/currency_format_utils.cpp
@@ -2585,7 +2585,7 @@ namespace currency
     return h - (h%CURRENCY_SCRATCHPAD_REBUILD_INTERVAL);
   }
   //-----------------------------------------------------------------------------------------------
-  uint64_t get_scratchpad_size_by_height(uint64_t h)
+  uint64_t get_scratchpad_size_for_height(uint64_t h)
   {
     //let's have ~256MB/year if block interval is 2 minutes
     return CURRENCY_SCRATCHPAD_BASE_SIZE + get_scratchpad_last_update_rebuild_height(h)*32;
diff --git a/src/currency_core/currency_format_utils.h b/src/currency_core/currency_format_utils.h
index 89802c58..0dfe58be 100644
--- a/src/currency_core/currency_format_utils.h
+++ b/src/currency_core/currency_format_utils.h
@@ -415,7 +415,7 @@ namespace currency
   bool get_block_reward(bool is_pos, size_t median_size, size_t current_block_size, uint64_t already_generated_coins, uint64_t &reward, uint64_t height);
   uint64_t get_base_block_reward(bool is_pos, uint64_t already_generated_coins, uint64_t height);
   uint64_t get_scratchpad_last_update_rebuild_height(uint64_t h);
-  uint64_t get_scratchpad_size_by_height(uint64_t h);
+  uint64_t get_scratchpad_size_for_height(uint64_t h);
   bool is_payment_id_size_ok(const std::string& payment_id);
   std::string get_account_address_as_str(const account_public_address& addr);
   std::string get_account_address_and_payment_id_as_str(const account_public_address& addr, const std::string& payment_id);
diff --git a/src/currency_core/scratchpad_helper.cpp b/src/currency_core/scratchpad_helper.cpp
index a74400ad..303ea533 100644
--- a/src/currency_core/scratchpad_helper.cpp
+++ b/src/currency_core/scratchpad_helper.cpp
@@ -14,16 +14,21 @@ namespace currency
 
   bool scratchpad_keeper::update(const std::vector<crypto::hash>& seed, uint64_t height)
   {
-    return crypto::generate_scratchpad(seed, m_scratchpad, get_scratchpad_size_by_height(height));
+    return crypto::generate_scratchpad(seed, m_scratchpad, get_scratchpad_size_for_height(height));
   }
   crypto::hash scratchpad_keeper::get_pow_hash(const blobdata& bd, uint64_t height)
   {
-    CHECK_AND_ASSERT_THROW_MES(get_scratchpad_size_by_height(height) == this->size(), "Fatal error on hash calculation: scratchpad_size=" << m_scratchpad.size() << " at height=" << height);
+    CHECK_AND_ASSERT_THROW_MES(get_scratchpad_size_for_height(height) == this->size(), "Fatal error on hash calculation: scratchpad_size=" << m_scratchpad.size() << " at height=" << height);
     crypto::hash res_hash = null_hash;
     bool res = get_wild_keccak2(bd, res_hash, m_scratchpad);
     CHECK_AND_ASSERT_THROW_MES(res, "Fatal error on hash calculation: scratchpad_size=" << m_scratchpad.size());
     return res_hash;
   }
+  crypto::hash scratchpad_keeper::get_pow_hash(const block& b)
+  {
+    blobdata bl = get_block_hashing_blob(b);
+    return get_pow_hash(bl, get_block_height(b));
+  }
   uint64_t scratchpad_keeper::size()
   {
     return m_scratchpad.size();
diff --git a/src/currency_core/scratchpad_helper.h b/src/currency_core/scratchpad_helper.h
index 949f10d1..9f2d93a9 100644
--- a/src/currency_core/scratchpad_helper.h
+++ b/src/currency_core/scratchpad_helper.h
@@ -4,7 +4,8 @@
 
 
 #include "crypto/wild_keccak.h"
-
+#include "currency_protocol/blobdatatype.h"
+#include "currency_core/currency_basic.h"
 
 namespace currency
 {
@@ -13,6 +14,7 @@ namespace currency
   public:
     bool update(const std::vector<crypto::hash>& seed, uint64_t height);
     crypto::hash get_pow_hash(const blobdata& bd, uint64_t height);
+    crypto::hash get_pow_hash(const block& b);
     uint64_t size();
   private:
     std::vector<crypto::hash> m_scratchpad;
diff --git a/src/currency_protocol/currency_protocol_handler.inl b/src/currency_protocol/currency_protocol_handler.inl
index 83917f92..f449fc52 100644
--- a/src/currency_protocol/currency_protocol_handler.inl
+++ b/src/currency_protocol/currency_protocol_handler.inl
@@ -114,7 +114,7 @@ namespace currency
   {
 
 
-    context.m_priv.m_remote_version = hshd.client_version;
+    context.m_remote_version = hshd.client_version;
 
     if(context.m_state == currency_connection_context::state_befor_handshake && !is_inital)
       return true;
diff --git a/src/p2p/net_node.inl b/src/p2p/net_node.inl
index 146d8cd8..4ccac2ba 100644
--- a/src/p2p/net_node.inl
+++ b/src/p2p/net_node.inl
@@ -1061,6 +1061,7 @@ namespace nodetool
       ce.time_started = cntxt.m_started;
       ce.last_recv = cntxt.m_last_recv;
       ce.last_send = cntxt.m_last_send;
+      ce.version = cntxt.m_remote_version;
       rsp.connections_list.push_back(ce);
       return true;
     });
diff --git a/src/p2p/p2p_protocol_defs.h b/src/p2p/p2p_protocol_defs.h
index 49d819b4..c7920678 100644
--- a/src/p2p/p2p_protocol_defs.h
+++ b/src/p2p/p2p_protocol_defs.h
@@ -41,6 +41,7 @@ namespace nodetool
     uint64_t time_started;
     uint64_t last_recv;
     uint64_t last_send;
+    std::string version;
   };
 
 #pragma pack(pop)
diff --git a/src/version.h.in b/src/version.h.in
index 092da955..f9120dc9 100644
--- a/src/version.h.in
+++ b/src/version.h.in
@@ -2,6 +2,6 @@
 
 #define BUILD_COMMIT_ID "@VERSION@"
 #define PROJECT_VERSION "1.0"
-#define PROJECT_VERSION_BUILD_NO 3
+#define PROJECT_VERSION_BUILD_NO 4
 #define PROJECT_VERSION_BUILD_NO_STR STRINGIFY_EXPAND(PROJECT_VERSION_BUILD_NO)
 #define PROJECT_VERSION_LONG PROJECT_VERSION "." PROJECT_VERSION_BUILD_NO_STR "[" BUILD_COMMIT_ID "]"