diff --git a/catchain/catchain-receiver.cpp b/catchain/catchain-receiver.cpp
index b9b0373f..e7f5c019 100644
--- a/catchain/catchain-receiver.cpp
+++ b/catchain/catchain-receiver.cpp
@@ -486,7 +486,7 @@ void CatChainReceiverImpl::start_up() {
   }
   td::actor::send_closure(overlay_manager_, &overlay::Overlays::create_private_overlay,
                           get_source(local_idx_)->get_adnl_id(), overlay_full_id_.clone(), std::move(ids),
-                          make_callback(), overlay::OverlayPrivacyRules{0, std::move(root_keys)});
+                          make_callback(), overlay::OverlayPrivacyRules{0, 0, std::move(root_keys)});
 
   CHECK(root_block_);
 
diff --git a/overlay/overlay-broadcast.cpp b/overlay/overlay-broadcast.cpp
index bade50e7..1c05f705 100644
--- a/overlay/overlay-broadcast.cpp
+++ b/overlay/overlay-broadcast.cpp
@@ -17,8 +17,14 @@
     Copyright 2017-2020 Telegram Systems LLP
 */
 #include "overlay-broadcast.hpp"
+#include "adnl/adnl-node-id.hpp"
+#include "common/util.h"
 #include "overlay.hpp"
 #include "keys/encryptor.h"
+#include "td/actor/PromiseFuture.h"
+#include "td/actor/actor.h"
+#include "td/utils/Status.h"
+#include "td/utils/port/Stat.h"
 
 namespace ton {
 
@@ -33,7 +39,13 @@ td::Status BroadcastSimple::check_duplicate() {
 }
 
 td::Status BroadcastSimple::check_source() {
-  return overlay_->check_source_eligible(source_, cert_.get(), data_size());
+  auto r = overlay_->check_source_eligible(source_, cert_.get(), data_size(), false);
+  if (r == BroadcastCheckResult::Forbidden) {
+    return td::Status::Error(ErrorCode::error, "broadcast is forbidden");
+  }
+
+  is_valid_ = r == BroadcastCheckResult::Allowed;
+  return td::Status::OK();
 }
 
 td::BufferSlice BroadcastSimple::to_sign() {
@@ -66,6 +78,14 @@ td::Status BroadcastSimple::distribute() {
   return td::Status::OK();
 }
 
+void BroadcastSimple::broadcast_checked(td::Result<td::Unit> R) {
+  if (R.is_error()) {
+    return;
+  }
+  is_valid_ = true;
+  run_continue().ignore();
+}
+
 tl_object_ptr<ton_api::overlay_broadcast> BroadcastSimple::tl() const {
   return create_tl_object<ton_api::overlay_broadcast>(source_.tl(), cert_ ? cert_->tl() : Certificate::empty_tl(),
                                                       flags_, data_.clone(), date_, signature_.clone());
@@ -75,6 +95,25 @@ td::BufferSlice BroadcastSimple::serialize() {
   return serialize_tl_object(tl(), true);
 }
 
+td::Status BroadcastSimple::run_continue() {
+  TRY_STATUS(distribute());
+  deliver();
+  return td::Status::OK();
+}
+
+td::Status BroadcastSimple::run() {
+  TRY_STATUS(run_checks());
+  if (!is_valid_) {
+    auto P = td::PromiseCreator::lambda(
+        [id = broadcast_hash_, overlay_id = actor_id(overlay_)](td::Result<td::Unit> R) mutable {
+          td::actor::send_closure(std::move(overlay_id), &OverlayImpl::broadcast_checked, id, std::move(R));
+        });
+    overlay_->check_broadcast(source_.compute_short_id(), data_.clone(), std::move(P));
+    return td::Status::OK();
+  }
+  return run_continue();
+}
+
 td::Status BroadcastSimple::create(OverlayImpl *overlay, tl_object_ptr<ton_api::overlay_broadcast> broadcast) {
   auto src = PublicKey{broadcast->src_};
   auto data_hash = sha256_bits256(broadcast->data_.as_slice());
@@ -86,7 +125,7 @@ td::Status BroadcastSimple::create(OverlayImpl *overlay, tl_object_ptr<ton_api::
 
   auto B = std::make_unique<BroadcastSimple>(broadcast_hash, src, std::move(cert), broadcast->flags_,
                                              std::move(broadcast->data_), broadcast->date_,
-                                             std::move(broadcast->signature_), overlay);
+                                             std::move(broadcast->signature_), false, overlay);
   TRY_STATUS(B->run());
   overlay->register_simple_broadcast(std::move(B));
   return td::Status::OK();
@@ -100,7 +139,7 @@ td::Status BroadcastSimple::create_new(td::actor::ActorId<OverlayImpl> overlay,
   auto date = static_cast<td::uint32>(td::Clocks::system());
 
   auto B = std::make_unique<BroadcastSimple>(broadcast_hash, PublicKey{}, nullptr, flags, std::move(data), date,
-                                             td::BufferSlice{}, nullptr);
+                                             td::BufferSlice{}, false, nullptr);
 
   auto to_sign = B->to_sign();
   auto P = td::PromiseCreator::lambda(
diff --git a/overlay/overlay-broadcast.hpp b/overlay/overlay-broadcast.hpp
index 665c269d..da29695a 100644
--- a/overlay/overlay-broadcast.hpp
+++ b/overlay/overlay-broadcast.hpp
@@ -18,9 +18,16 @@
 */
 #pragma once
 
+#include "adnl/adnl-local-id.h"
+#include "adnl/adnl-node-id.hpp"
 #include "auto/tl/ton_api.h"
+#include "common/refcnt.hpp"
 #include "overlay/overlay.h"
+#include "td/actor/PromiseFuture.h"
 #include "td/utils/List.h"
+#include "td/utils/Status.h"
+#include "td/utils/buffer.h"
+#include "td/utils/common.h"
 
 namespace ton {
 
@@ -38,6 +45,7 @@ class BroadcastSimple : public td::ListNode {
   td::BufferSlice data_;
   td::uint32 date_;
   td::BufferSlice signature_;
+  bool is_valid_{false};
 
   OverlayImpl *overlay_;
 
@@ -52,7 +60,7 @@ class BroadcastSimple : public td::ListNode {
 
  public:
   BroadcastSimple(Overlay::BroadcastHash broadcast_hash, PublicKey source, std::shared_ptr<Certificate> cert,
-                  td::uint32 flags, td::BufferSlice data, td::uint32 date, td::BufferSlice signature,
+                  td::uint32 flags, td::BufferSlice data, td::uint32 date, td::BufferSlice signature, bool is_valid,
                   OverlayImpl *overlay)
       : broadcast_hash_(broadcast_hash)
       , source_(std::move(source))
@@ -61,6 +69,7 @@ class BroadcastSimple : public td::ListNode {
       , data_(std::move(data))
       , date_(date)
       , signature_(std::move(signature))
+      , is_valid_(is_valid)
       , overlay_(overlay) {
   }
 
@@ -80,17 +89,14 @@ class BroadcastSimple : public td::ListNode {
   }
   void deliver();
 
-  td::Status run() {
-    TRY_STATUS(run_checks());
-    TRY_STATUS(distribute());
-    deliver();
-    return td::Status::OK();
-  }
+  td::Status run();
+  td::Status run_continue();
 
   tl_object_ptr<ton_api::overlay_broadcast> tl() const;
   td::BufferSlice serialize();
 
   void update_overlay(OverlayImpl *overlay);
+  void broadcast_checked(td::Result<td::Unit> R);
 
   static td::Status create(OverlayImpl *overlay, tl_object_ptr<ton_api::overlay_broadcast> broadcast);
   static td::Status create_new(td::actor::ActorId<OverlayImpl> overlay, td::actor::ActorId<keyring::Keyring> keyring,
diff --git a/overlay/overlay-fec-broadcast.cpp b/overlay/overlay-fec-broadcast.cpp
index e368c620..6ab03800 100644
--- a/overlay/overlay-fec-broadcast.cpp
+++ b/overlay/overlay-fec-broadcast.cpp
@@ -54,7 +54,16 @@ td::Status OverlayFecBroadcastPart::check_duplicate() {
 }
 
 td::Status OverlayFecBroadcastPart::check_source() {
-  TRY_STATUS(overlay_->check_source_eligible(source_, cert_.get(), broadcast_size_));
+  auto r = overlay_->check_source_eligible(source_, cert_.get(), broadcast_size_, true);
+  if (r == BroadcastCheckResult::Forbidden) {
+    return td::Status::Error(ErrorCode::error, "broadcast is forbidden");
+  }
+
+  // FIXME
+  if (r == BroadcastCheckResult::NeedCheck) {
+    return td::Status::Error(ErrorCode::error, "broadcast is forbidden");
+  }
+
   if (bcast_) {
     TRY_STATUS(bcast_->is_eligible_sender(source_));
   }
diff --git a/overlay/overlay-fec-broadcast.hpp b/overlay/overlay-fec-broadcast.hpp
index 6d30d47c..0ce9c2ff 100644
--- a/overlay/overlay-fec-broadcast.hpp
+++ b/overlay/overlay-fec-broadcast.hpp
@@ -185,6 +185,9 @@ class BroadcastFec : public td::ListNode {
     }
   }
 
+  void broadcast_checked(td::Result<td::Unit> R) {
+  }
+
  private:
   bool ready_ = false;
 
@@ -311,4 +314,3 @@ class OverlayFecBroadcastPart : public td::ListNode {
 }  // namespace overlay
 
 }  // namespace ton
-
diff --git a/overlay/overlay-manager.cpp b/overlay/overlay-manager.cpp
index ae7c3dd5..059ad4e2 100644
--- a/overlay/overlay-manager.cpp
+++ b/overlay/overlay-manager.cpp
@@ -17,6 +17,7 @@
     Copyright 2017-2020 Telegram Systems LLP
 */
 #include "overlay-manager.h"
+#include "auto/tl/ton_api.h"
 #include "overlay.h"
 
 #include "adnl/utils.hpp"
@@ -268,17 +269,21 @@ void OverlayManager::save_to_db(adnl::AdnlNodeIdShort local_id, OverlayIdShort o
   db_.set(key, create_serialize_tl_object<ton_api::overlay_db_nodes>(std::move(obj)));
 }
 
-Certificate::Certificate(PublicKey issued_by, td::int32 expire_at, td::uint32 max_size, td::BufferSlice signature)
+Certificate::Certificate(PublicKey issued_by, td::int32 expire_at, td::uint32 max_size, td::uint32 flags,
+                         td::BufferSlice signature)
     : issued_by_(issued_by)
     , expire_at_(expire_at)
     , max_size_(max_size)
+    , flags_(flags)
     , signature_(td::SharedSlice(signature.as_slice())) {
 }
 
-Certificate::Certificate(PublicKeyHash issued_by, td::int32 expire_at, td::uint32 max_size, td::BufferSlice signature)
+Certificate::Certificate(PublicKeyHash issued_by, td::int32 expire_at, td::uint32 max_size, td::uint32 flags,
+                         td::BufferSlice signature)
     : issued_by_(issued_by)
     , expire_at_(expire_at)
     , max_size_(max_size)
+    , flags_(flags)
     , signature_(td::SharedSlice(signature.as_slice())) {
 }
 
@@ -290,9 +295,19 @@ void Certificate::set_issuer(PublicKey issuer) {
   issued_by_ = issuer;
 }
 
+constexpr td::uint32 cert_default_flags(td::uint32 max_size) {
+  return (max_size > Overlays::max_simple_broadcast_size() ? CertificateFlags::AllowFec : 0) |
+         CertificateFlags::Trusted;
+}
+
 td::BufferSlice Certificate::to_sign(OverlayIdShort overlay_id, PublicKeyHash issued_to) const {
-  return create_serialize_tl_object<ton_api::overlay_certificateId>(overlay_id.tl(), issued_to.tl(), expire_at_,
-                                                                    max_size_);
+  if (flags_ == cert_default_flags(max_size_)) {
+    return create_serialize_tl_object<ton_api::overlay_certificateId>(overlay_id.tl(), issued_to.tl(), expire_at_,
+                                                                      max_size_);
+  } else {
+    return create_serialize_tl_object<ton_api::overlay_certificateIdV2>(overlay_id.tl(), issued_to.tl(), expire_at_,
+                                                                        max_size_, flags_);
+  }
 }
 
 const PublicKeyHash Certificate::issuer_hash() const {
@@ -307,32 +322,48 @@ const PublicKey &Certificate::issuer() const {
 
 td::Result<std::shared_ptr<Certificate>> Certificate::create(tl_object_ptr<ton_api::overlay_Certificate> cert) {
   std::shared_ptr<Certificate> res;
-  ton_api::downcast_call(*cert.get(), td::overloaded([&](ton_api::overlay_emptyCertificate &obj) { res = nullptr; },
-                                                     [&](ton_api::overlay_certificate &obj) {
-                                                       res = std::make_shared<Certificate>(
-                                                           PublicKey{obj.issued_by_}, obj.expire_at_,
-                                                           static_cast<td::uint32>(obj.max_size_),
-                                                           std::move(obj.signature_));
-                                                     }));
+  ton_api::downcast_call(*cert.get(),
+                         td::overloaded([&](ton_api::overlay_emptyCertificate &obj) { res = nullptr; },
+                                        [&](ton_api::overlay_certificate &obj) {
+                                          res = std::make_shared<Certificate>(PublicKey{obj.issued_by_}, obj.expire_at_,
+                                                                              static_cast<td::uint32>(obj.max_size_),
+                                                                              cert_default_flags(obj.max_size_),
+                                                                              std::move(obj.signature_));
+                                        },
+                                        [&](ton_api::overlay_certificateV2 &obj) {
+                                          res = std::make_shared<Certificate>(PublicKey{obj.issued_by_}, obj.expire_at_,
+                                                                              static_cast<td::uint32>(obj.max_size_),
+                                                                              static_cast<td::uint32>(obj.flags_),
+                                                                              std::move(obj.signature_));
+                                        }));
   return std::move(res);
 }
 
-td::Status Certificate::check(PublicKeyHash node, OverlayIdShort overlay_id, td::int32 unix_time,
-                              td::uint32 size) const {
+BroadcastCheckResult Certificate::check(PublicKeyHash node, OverlayIdShort overlay_id, td::int32 unix_time,
+                                        td::uint32 size, bool is_fec) const {
   if (size > max_size_) {
-    return td::Status::Error(ErrorCode::protoviolation, "too big broadcast size");
+    return BroadcastCheckResult::Forbidden;
   }
   if (unix_time > expire_at_) {
-    return td::Status::Error(ErrorCode::protoviolation, "too old certificate");
+    return BroadcastCheckResult::Forbidden;
+  }
+  if (is_fec && !(flags_ & CertificateFlags::AllowFec)) {
+    return BroadcastCheckResult::Forbidden;
   }
 
-  TRY_RESULT(E, issued_by_.get<PublicKey>().create_encryptor());
+  auto R1 = issued_by_.get<PublicKey>().create_encryptor();
+  if (R1.is_error()) {
+    return BroadcastCheckResult::Forbidden;
+  }
+  auto E = R1.move_as_ok();
 
   auto B = to_sign(overlay_id, node);
 
-  TRY_STATUS(E->check_signature(B.as_slice(), signature_.as_slice()));
+  if (E->check_signature(B.as_slice(), signature_.as_slice()).is_error()) {
+    return BroadcastCheckResult::Forbidden;
+  }
 
-  return td::Status::OK();
+  return (flags_ & CertificateFlags::Trusted) ? BroadcastCheckResult::Allowed : BroadcastCheckResult::NeedCheck;
 }
 
 tl_object_ptr<ton_api::overlay_Certificate> Certificate::tl() const {
diff --git a/overlay/overlay.cpp b/overlay/overlay.cpp
index 47019c16..21ec9363 100644
--- a/overlay/overlay.cpp
+++ b/overlay/overlay.cpp
@@ -391,25 +391,21 @@ td::Status OverlayImpl::check_date(td::uint32 date) {
   return td::Status::OK();
 }
 
-td::Status OverlayImpl::check_source_eligible(PublicKey source, const Certificate *cert, td::uint32 size) {
+BroadcastCheckResult OverlayImpl::check_source_eligible(PublicKey source, const Certificate *cert, td::uint32 size,
+                                                        bool is_fec) {
   if (size == 0) {
-    return td::Status::Error(ErrorCode::protoviolation, "empty broadcast");
+    return BroadcastCheckResult::Forbidden;
   }
   auto short_id = source.compute_short_id();
 
-  auto r = rules_.max_size(source.compute_short_id());
-  if (r >= size) {
-    return td::Status::OK();
+  auto r = rules_.check_rules(source.compute_short_id(), size, is_fec);
+  if (!cert || r == BroadcastCheckResult::Allowed) {
+    return r;
   }
-  if (!cert) {
-    return td::Status::Error(ErrorCode::protoviolation, "source is not eligible");
-  }
-  TRY_STATUS(cert->check(short_id, overlay_id_, static_cast<td::int32>(td::Clocks::system()), size));
-  auto issuer_short = cert->issuer_hash();
-  if (rules_.max_size(issuer_short) < size) {
-    return td::Status::Error(ErrorCode::protoviolation, "bad certificate");
-  }
-  return td::Status::OK();
+
+  auto r2 = cert->check(short_id, overlay_id_, static_cast<td::int32>(td::Clocks::system()), size, is_fec);
+  r2 = broadcast_check_result_min(r2, rules_.check_rules(cert->issuer_hash(), size, is_fec));
+  return broadcast_check_result_max(r, r2);
 }
 
 td::Status OverlayImpl::check_delivered(BroadcastHash hash) {
@@ -539,6 +535,25 @@ void OverlayImpl::set_privacy_rules(OverlayPrivacyRules rules) {
   rules_ = std::move(rules);
 }
 
+void OverlayImpl::check_broadcast(PublicKeyHash src, td::BufferSlice data, td::Promise<td::Unit> promise) {
+  callback_->check_broadcast(src, overlay_id_, std::move(data), std::move(promise));
+}
+
+void OverlayImpl::broadcast_checked(Overlay::BroadcastHash hash, td::Result<td::Unit> R) {
+  {
+    auto it = broadcasts_.find(hash);
+    if (it != broadcasts_.end()) {
+      it->second->broadcast_checked(std::move(R));
+    }
+  }
+  {
+    auto it = fec_broadcasts_.find(hash);
+    if (it != fec_broadcasts_.end()) {
+      it->second->broadcast_checked(std::move(R));
+    }
+  }
+}
+
 }  // namespace overlay
 
 }  // namespace ton
diff --git a/overlay/overlay.hpp b/overlay/overlay.hpp
index b087fc75..cbddd654 100644
--- a/overlay/overlay.hpp
+++ b/overlay/overlay.hpp
@@ -144,9 +144,12 @@ class OverlayImpl : public Overlay {
   void print(td::StringBuilder &sb) override;
 
   td::Status check_date(td::uint32 date);
-  td::Status check_source_eligible(PublicKey source, const Certificate *cert, td::uint32 size);
+  BroadcastCheckResult check_source_eligible(PublicKey source, const Certificate *cert, td::uint32 size, bool is_fec);
   td::Status check_delivered(BroadcastHash hash);
 
+  void broadcast_checked(Overlay::BroadcastHash hash, td::Result<td::Unit> R);
+  void check_broadcast(PublicKeyHash src, td::BufferSlice data, td::Promise<td::Unit> promise);
+
   BroadcastFec *get_fec_broadcast(BroadcastHash hash);
   void register_fec_broadcast(std::unique_ptr<BroadcastFec> bcast);
   void register_simple_broadcast(std::unique_ptr<BroadcastSimple> bcast);
diff --git a/overlay/overlays.h b/overlay/overlays.h
index 90f3877e..1ad55453 100644
--- a/overlay/overlays.h
+++ b/overlay/overlays.h
@@ -21,7 +21,11 @@
 #include "adnl/adnl.h"
 #include "dht/dht.h"
 
+#include "td/actor/PromiseFuture.h"
 #include "td/actor/actor.h"
+#include "td/utils/Status.h"
+#include "td/utils/buffer.h"
+#include "td/utils/common.h"
 
 #include <map>
 
@@ -80,41 +84,64 @@ class OverlayIdFull {
   td::BufferSlice name_;
 };
 
+struct CertificateFlags {
+  enum Values : td::uint32 { AllowFec = 1, Trusted = 2 };
+};
+
+enum BroadcastCheckResult { Forbidden = 1, NeedCheck = 2, Allowed = 3 };
+
+inline BroadcastCheckResult broadcast_check_result_max(BroadcastCheckResult l, BroadcastCheckResult r) {
+  return static_cast<BroadcastCheckResult>(std::max(static_cast<td::int32>(l), static_cast<td::int32>(r)));
+}
+inline BroadcastCheckResult broadcast_check_result_min(BroadcastCheckResult l, BroadcastCheckResult r) {
+  return static_cast<BroadcastCheckResult>(std::min(static_cast<td::int32>(l), static_cast<td::int32>(r)));
+}
+
 class OverlayPrivacyRules {
  public:
   OverlayPrivacyRules() {
   }
   OverlayPrivacyRules(td::uint32 size) : max_unath_size_(size) {
   }
-  OverlayPrivacyRules(td::uint32 max_size, std::map<PublicKeyHash, td::uint32> authorized_keys)
-      : max_unath_size_(max_size), authorized_keys_(std::move(authorized_keys)) {
+  OverlayPrivacyRules(td::uint32 max_size, td::uint32 flags, std::map<PublicKeyHash, td::uint32> authorized_keys)
+      : max_unath_size_(max_size), flags_(flags), authorized_keys_(std::move(authorized_keys)) {
   }
 
-  td::uint32 max_size(PublicKeyHash hash) {
+  BroadcastCheckResult check_rules(PublicKeyHash hash, td::uint32 size, bool is_fec) {
     auto it = authorized_keys_.find(hash);
     if (it == authorized_keys_.end()) {
-      return max_unath_size_;
+      if (size > max_unath_size_) {
+        return BroadcastCheckResult::Forbidden;
+      }
+      if (!(flags_ & CertificateFlags::AllowFec) && is_fec) {
+        return BroadcastCheckResult::Forbidden;
+      }
+      return (flags_ & CertificateFlags::Trusted) ? BroadcastCheckResult::Allowed : BroadcastCheckResult::NeedCheck;
     } else {
-      return it->second;
+      return it->second >= size ? BroadcastCheckResult::Allowed : BroadcastCheckResult::Forbidden;
     }
   }
 
  private:
   td::uint32 max_unath_size_{0};
+  td::uint32 flags_{0};
   std::map<PublicKeyHash, td::uint32> authorized_keys_;
 };
 
 class Certificate {
  public:
-  Certificate(PublicKeyHash issued_by, td::int32 expire_at, td::uint32 max_size, td::BufferSlice signature);
-  Certificate(PublicKey issued_by, td::int32 expire_at, td::uint32 max_size, td::BufferSlice signature);
+  Certificate(PublicKeyHash issued_by, td::int32 expire_at, td::uint32 max_size, td::uint32 flags,
+              td::BufferSlice signature);
+  Certificate(PublicKey issued_by, td::int32 expire_at, td::uint32 max_size, td::uint32 flags,
+              td::BufferSlice signature);
   Certificate() {
   }
   void set_signature(td::BufferSlice signature);
   void set_issuer(PublicKey issuer);
   td::BufferSlice to_sign(OverlayIdShort overlay_id, PublicKeyHash issued_to) const;
 
-  td::Status check(PublicKeyHash node, OverlayIdShort overlay_id, td::int32 unix_time, td::uint32 size) const;
+  BroadcastCheckResult check(PublicKeyHash node, OverlayIdShort overlay_id, td::int32 unix_time, td::uint32 size,
+                             bool is_fec) const;
   tl_object_ptr<ton_api::overlay_Certificate> tl() const;
   const PublicKey &issuer() const;
   const PublicKeyHash issuer_hash() const;
@@ -126,6 +153,7 @@ class Certificate {
   td::Variant<PublicKey, PublicKeyHash> issued_by_;
   td::int32 expire_at_;
   td::uint32 max_size_;
+  td::uint32 flags_;
   td::SharedSlice signature_;
 };
 
@@ -137,6 +165,10 @@ class Overlays : public td::actor::Actor {
     virtual void receive_query(adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id, td::BufferSlice data,
                                td::Promise<td::BufferSlice> promise) = 0;
     virtual void receive_broadcast(PublicKeyHash src, OverlayIdShort overlay_id, td::BufferSlice data) = 0;
+    virtual void check_broadcast(PublicKeyHash src, OverlayIdShort overlay_id, td::BufferSlice data,
+                                 td::Promise<td::Unit> promise) {
+      promise.set_value(td::Unit());
+    }
     virtual ~Callback() = default;
   };
 
diff --git a/tl/generate/scheme/ton_api.tl b/tl/generate/scheme/ton_api.tl
index 57ed9ddc..b226ca7f 100644
--- a/tl/generate/scheme/ton_api.tl
+++ b/tl/generate/scheme/ton_api.tl
@@ -219,9 +219,11 @@ overlay.broadcastFec.partId broadcast_hash:int256 data_hash:int256 seqno:int = o
 overlay.broadcast.toSign hash:int256 date:int = overlay.broadcast.ToSign;
 
 overlay.certificate issued_by:PublicKey expire_at:int max_size:int signature:bytes = overlay.Certificate;
+overlay.certificateV2 issued_by:PublicKey expire_at:int max_size:int flags:int signature:bytes = overlay.Certificate;
 overlay.emptyCertificate = overlay.Certificate;
 
 overlay.certificateId overlay_id:int256 node:int256 expire_at:int max_size:int = overlay.CertificateId;
+overlay.certificateIdV2 overlay_id:int256 node:int256 expire_at:int max_size:int flags:int = overlay.CertificateId;
 
 overlay.unicast data:bytes = overlay.Broadcast;
 overlay.broadcast src:PublicKey certificate:overlay.Certificate flags:int data:bytes date:int signature:bytes = overlay.Broadcast;
diff --git a/tl/generate/scheme/ton_api.tlo b/tl/generate/scheme/ton_api.tlo
index 823219b5..32f42b3c 100644
Binary files a/tl/generate/scheme/ton_api.tlo and b/tl/generate/scheme/ton_api.tlo differ
diff --git a/validator/full-node-shard.cpp b/validator/full-node-shard.cpp
index bc295992..769ef8f3 100644
--- a/validator/full-node-shard.cpp
+++ b/validator/full-node-shard.cpp
@@ -16,6 +16,8 @@
 
     Copyright 2017-2020 Telegram Systems LLP
 */
+#include "auto/tl/ton_api.h"
+#include "overlays.h"
 #include "td/utils/SharedSlice.h"
 #include "full-node-shard.hpp"
 #include "full-node-shard-queries.hpp"
@@ -79,6 +81,10 @@ void FullNodeShardImpl::create_overlay() {
     void receive_broadcast(PublicKeyHash src, overlay::OverlayIdShort overlay_id, td::BufferSlice data) override {
       td::actor::send_closure(node_, &FullNodeShardImpl::receive_broadcast, src, std::move(data));
     }
+    void check_broadcast(PublicKeyHash src, overlay::OverlayIdShort overlay_id, td::BufferSlice data,
+                         td::Promise<td::Unit> promise) override {
+      td::actor::send_closure(node_, &FullNodeShardImpl::check_broadcast, src, std::move(data), std::move(promise));
+    }
     Callback(td::actor::ActorId<FullNodeShardImpl> node) : node_(node) {
     }
 
@@ -95,6 +101,17 @@ void FullNodeShardImpl::create_overlay() {
   }
 }
 
+void FullNodeShardImpl::check_broadcast(PublicKeyHash src, td::BufferSlice broadcast, td::Promise<td::Unit> promise) {
+  auto B = fetch_tl_object<ton_api::tonNode_externalMessageBroadcast>(std::move(broadcast), true);
+  if (B.is_error()) {
+    return promise.set_error(B.move_as_error_prefix("failed to parse external message broadcast: "));
+  }
+
+  auto q = B.move_as_ok();
+  td::actor::send_closure(validator_manager_, &ValidatorManagerInterface::check_external_message,
+                          std::move(q->message_->data_), std::move(promise));
+}
+
 void FullNodeShardImpl::update_adnl_id(adnl::AdnlNodeIdShort adnl_id, td::Promise<td::Unit> promise) {
   td::actor::send_closure(overlays_, &ton::overlay::Overlays::delete_overlay, adnl_id_, overlay_id_);
   adnl_id_ = adnl_id;
@@ -804,8 +821,9 @@ void FullNodeShardImpl::sign_new_certificate(PublicKeyHash sign_by) {
     return;
   }
 
-  ton::overlay::Certificate cert{sign_by, static_cast<td::int32>(td::Clocks::system() + 3600),
-                                 overlay::Overlays::max_fec_broadcast_size(), td::BufferSlice{}};
+  ton::overlay::Certificate cert{
+      sign_by, static_cast<td::int32>(td::Clocks::system() + 3600), overlay::Overlays::max_fec_broadcast_size(),
+      overlay::CertificateFlags::Trusted | overlay::CertificateFlags::AllowFec, td::BufferSlice{}};
   auto to_sign = cert.to_sign(overlay_id_, local_id_);
 
   auto P = td::PromiseCreator::lambda(
@@ -845,7 +863,7 @@ void FullNodeShardImpl::update_validators(std::vector<PublicKeyHash> public_key_
     authorized_keys.emplace(key, overlay::Overlays::max_fec_broadcast_size());
   }
 
-  rules_ = overlay::OverlayPrivacyRules{1 << 14, std::move(authorized_keys)};
+  rules_ = overlay::OverlayPrivacyRules{1 << 14, 0, std::move(authorized_keys)};
   td::actor::send_closure(overlays_, &overlay::Overlays::set_privacy_rules, adnl_id_, overlay_id_, rules_);
 
   if (update_cert) {
@@ -949,8 +967,7 @@ void FullNodeShardImpl::update_neighbour_stats(adnl::AdnlNodeIdShort adnl_id, do
   }
 }
 
-void FullNodeShardImpl::got_neighbour_capabilities(adnl::AdnlNodeIdShort adnl_id, double t,
-                                                   td::BufferSlice data) {
+void FullNodeShardImpl::got_neighbour_capabilities(adnl::AdnlNodeIdShort adnl_id, double t, td::BufferSlice data) {
   auto it = neighbours_.find(adnl_id);
   if (it == neighbours_.end()) {
     return;
diff --git a/validator/full-node-shard.hpp b/validator/full-node-shard.hpp
index 4aad637b..2c468374 100644
--- a/validator/full-node-shard.hpp
+++ b/validator/full-node-shard.hpp
@@ -19,6 +19,8 @@
 #pragma once
 
 #include "full-node-shard.h"
+#include "td/actor/PromiseFuture.h"
+#include "td/utils/port/Poll.h"
 
 namespace ton {
 
@@ -139,6 +141,7 @@ class FullNodeShardImpl : public FullNodeShard {
   void process_broadcast(PublicKeyHash src, ton_api::tonNode_externalMessageBroadcast &query);
   void process_broadcast(PublicKeyHash src, ton_api::tonNode_newShardBlockBroadcast &query);
   void receive_broadcast(PublicKeyHash src, td::BufferSlice query);
+  void check_broadcast(PublicKeyHash src, td::BufferSlice query, td::Promise<td::Unit> promise);
 
   void send_ihr_message(td::BufferSlice data) override;
   void send_external_message(td::BufferSlice data) override;
diff --git a/validator/manager-disk.hpp b/validator/manager-disk.hpp
index 71818e6e..fa365ccf 100644
--- a/validator/manager-disk.hpp
+++ b/validator/manager-disk.hpp
@@ -124,6 +124,9 @@ class ValidatorManagerImpl : public ValidatorManager {
   //void get_block_description(BlockIdExt block_id, td::Promise<BlockDescription> promise) override;
 
   void new_external_message(td::BufferSlice data) override;
+  void check_external_message(td::BufferSlice data, td::Promise<td::Unit> promise) override {
+    UNREACHABLE();
+  }
   void new_ihr_message(td::BufferSlice data) override;
   void new_shard_block(BlockIdExt block_id, CatchainSeqno cc_seqno, td::BufferSlice data) override;
 
diff --git a/validator/manager-hardfork.hpp b/validator/manager-hardfork.hpp
index 506ee036..9938bcb2 100644
--- a/validator/manager-hardfork.hpp
+++ b/validator/manager-hardfork.hpp
@@ -144,6 +144,9 @@ class ValidatorManagerImpl : public ValidatorManager {
   void get_key_block_proof_link(BlockIdExt block_id, td::Promise<td::BufferSlice> promise) override;
 
   void new_external_message(td::BufferSlice data) override;
+  void check_external_message(td::BufferSlice data, td::Promise<td::Unit> promise) override {
+    UNREACHABLE();
+  }
   void new_ihr_message(td::BufferSlice data) override;
   void new_shard_block(BlockIdExt block_id, CatchainSeqno cc_seqno, td::BufferSlice data) override {
     UNREACHABLE();
diff --git a/validator/manager.hpp b/validator/manager.hpp
index 672085d0..08de5060 100644
--- a/validator/manager.hpp
+++ b/validator/manager.hpp
@@ -20,6 +20,8 @@
 
 #include "interfaces/validator-manager.h"
 #include "interfaces/db.h"
+#include "td/actor/PromiseFuture.h"
+#include "td/utils/port/Poll.h"
 #include "validator-group.hpp"
 #include "shard-client.hpp"
 #include "manager-init.h"
@@ -325,6 +327,9 @@ class ValidatorManagerImpl : public ValidatorManager {
   //void get_block_description(BlockIdExt block_id, td::Promise<BlockDescription> promise) override;
 
   void new_external_message(td::BufferSlice data) override;
+  void check_external_message(td::BufferSlice data, td::Promise<td::Unit> promise) override {
+    promise.set_value(td::Unit());
+  }
   void new_ihr_message(td::BufferSlice data) override;
   void new_shard_block(BlockIdExt block_id, CatchainSeqno cc_seqno, td::BufferSlice data) override;
 
diff --git a/validator/validator.h b/validator/validator.h
index 54c35ee7..0cbdbe00 100644
--- a/validator/validator.h
+++ b/validator/validator.h
@@ -94,9 +94,8 @@ struct ValidatorManagerOptions : public td::CntObject {
       BlockIdExt zero_block_id, BlockIdExt init_block_id,
       std::function<bool(ShardIdFull, CatchainSeqno, ShardCheckMode)> check_shard = [](ShardIdFull, CatchainSeqno,
                                                                                        ShardCheckMode) { return true; },
-      bool allow_blockchain_init = false, double sync_blocks_before = 300,
-      double block_ttl = 86400 * 7, double state_ttl = 3600,
-      double archive_ttl = 86400 * 365, double key_proof_ttl = 86400 * 3650,
+      bool allow_blockchain_init = false, double sync_blocks_before = 300, double block_ttl = 86400 * 7,
+      double state_ttl = 3600, double archive_ttl = 86400 * 365, double key_proof_ttl = 86400 * 3650,
       bool initial_sync_disabled = false);
 };
 
@@ -176,6 +175,7 @@ class ValidatorManagerInterface : public td::actor::Actor {
   virtual void write_handle(BlockHandle handle, td::Promise<td::Unit> promise) = 0;
 
   virtual void new_external_message(td::BufferSlice data) = 0;
+  virtual void check_external_message(td::BufferSlice data, td::Promise<td::Unit> promise) = 0;
   virtual void new_ihr_message(td::BufferSlice data) = 0;
   virtual void new_shard_block(BlockIdExt block_id, CatchainSeqno cc_seqno, td::BufferSlice data) = 0;