bulletproofs: add multi output bulletproofs to rct

9 files changed, 181 insertions, 94 deletions

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index e96dc6bb6..c815b507e 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -3059,6 +3059,22 @@ bool Blockchain::check_tx_inputs(transaction& tx, tx_verification_context &tvc,
       MERROR_VER("Unsupported rct type: " << rv.type);
       return false;
     }
+
+    // for bulletproofs, check they're only multi-output after v8
+    if (rv.type == rct::RCTTypeFullBulletproof || rv.type == rct::RCTTypeSimpleBulletproof)
+    {
+      if (hf_version < 8)
+      {
+        for (const rct::Bulletproof &proof: rv.p.bulletproofs)
+        {
+          if (proof.V.size() > 1)
+          {
+            MERROR_VER("Multi output bulletproofs are invalid before v8");
+            return false;
+          }
+        }
+      }
+    }
   }
   return true;
 }
diff --git a/src/cryptonote_core/cryptonote_tx_utils.cpp b/src/cryptonote_core/cryptonote_tx_utils.cpp
index 1581f3088..32031e950 100644
--- a/src/cryptonote_core/cryptonote_tx_utils.cpp
+++ b/src/cryptonote_core/cryptonote_tx_utils.cpp
@@ -195,7 +195,7 @@ namespace cryptonote
     return addr.m_view_public_key;
   }
   //---------------------------------------------------------------
-  bool construct_tx_with_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, const crypto::secret_key &tx_key, const std::vector<crypto::secret_key> &additional_tx_keys, bool rct, bool bulletproof, rct::multisig_out *msout, bool shuffle_outs)
+  bool construct_tx_with_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, const crypto::secret_key &tx_key, const std::vector<crypto::secret_key> &additional_tx_keys, bool rct, rct::RangeProofType range_proof_type, rct::multisig_out *msout, bool shuffle_outs)
   {
     hw::device &hwdev = sender_account_keys.get_device();
 
@@ -589,9 +589,9 @@ namespace cryptonote
       get_transaction_prefix_hash(tx, tx_prefix_hash);
       rct::ctkeyV outSk;
       if (use_simple_rct)
-        tx.rct_signatures = rct::genRctSimple(rct::hash2rct(tx_prefix_hash), inSk, destinations, inamounts, outamounts, amount_in - amount_out, mixRing, amount_keys, msout ? &kLRki : NULL, msout, index, outSk, bulletproof, hwdev);
+        tx.rct_signatures = rct::genRctSimple(rct::hash2rct(tx_prefix_hash), inSk, destinations, inamounts, outamounts, amount_in - amount_out, mixRing, amount_keys, msout ? &kLRki : NULL, msout, index, outSk, range_proof_type, hwdev);
       else
-        tx.rct_signatures = rct::genRct(rct::hash2rct(tx_prefix_hash), inSk, destinations, outamounts, mixRing, amount_keys, msout ? &kLRki[0] : NULL, msout, sources[0].real_output, outSk, bulletproof, hwdev); // same index assumption
+        tx.rct_signatures = rct::genRct(rct::hash2rct(tx_prefix_hash), inSk, destinations, outamounts, mixRing, amount_keys, msout ? &kLRki[0] : NULL, msout, sources[0].real_output, outSk, range_proof_type, hwdev); // same index assumption
       memwipe(inSk.data(), inSk.size() * sizeof(rct::ctkey));
 
       CHECK_AND_ASSERT_MES(tx.vout.size() == outSk.size(), false, "outSk size does not match vout");
@@ -604,7 +604,7 @@ namespace cryptonote
     return true;
   }
   //---------------------------------------------------------------
-  bool construct_tx_and_get_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, crypto::secret_key &tx_key, std::vector<crypto::secret_key> &additional_tx_keys, bool rct, bool bulletproof, rct::multisig_out *msout)
+  bool construct_tx_and_get_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, crypto::secret_key &tx_key, std::vector<crypto::secret_key> &additional_tx_keys, bool rct, rct::RangeProofType range_proof_type, rct::multisig_out *msout)
   {
     hw::device &hwdev = sender_account_keys.get_device();
     hwdev.open_tx(tx_key);
@@ -622,7 +622,7 @@ namespace cryptonote
         additional_tx_keys.push_back(keypair::generate(sender_account_keys.get_device()).sec);
     }
 
-    bool r = construct_tx_with_tx_key(sender_account_keys, subaddresses, sources, destinations, change_addr, extra, tx, unlock_time, tx_key, additional_tx_keys, rct, bulletproof, msout);
+    bool r = construct_tx_with_tx_key(sender_account_keys, subaddresses, sources, destinations, change_addr, extra, tx, unlock_time, tx_key, additional_tx_keys, rct, range_proof_type, msout);
     hwdev.close_tx();
     return r;
   }
@@ -634,7 +634,7 @@ namespace cryptonote
      crypto::secret_key tx_key;
      std::vector<crypto::secret_key> additional_tx_keys;
      std::vector<tx_destination_entry> destinations_copy = destinations;
-     return construct_tx_and_get_tx_key(sender_account_keys, subaddresses, sources, destinations_copy, change_addr, extra, tx, unlock_time, tx_key, additional_tx_keys, false, false, NULL);
+     return construct_tx_and_get_tx_key(sender_account_keys, subaddresses, sources, destinations_copy, change_addr, extra, tx, unlock_time, tx_key, additional_tx_keys, false, rct::RangeProofBorromean, NULL);
   }
   //---------------------------------------------------------------
   bool generate_genesis_block(
diff --git a/src/cryptonote_core/cryptonote_tx_utils.h b/src/cryptonote_core/cryptonote_tx_utils.h
index a5d149fca..08e8725f7 100644
--- a/src/cryptonote_core/cryptonote_tx_utils.h
+++ b/src/cryptonote_core/cryptonote_tx_utils.h
@@ -90,8 +90,8 @@ namespace cryptonote
   //---------------------------------------------------------------
   crypto::public_key get_destination_view_key_pub(const std::vector<tx_destination_entry> &destinations, const boost::optional<cryptonote::account_public_address>& change_addr);
   bool construct_tx(const account_keys& sender_account_keys, std::vector<tx_source_entry> &sources, const std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time);
-  bool construct_tx_with_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, const crypto::secret_key &tx_key, const std::vector<crypto::secret_key> &additional_tx_keys, bool rct = false, bool bulletproof = false, rct::multisig_out *msout = NULL, bool shuffle_outs = true);
-  bool construct_tx_and_get_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, crypto::secret_key &tx_key, std::vector<crypto::secret_key> &additional_tx_keys, bool rct = false, bool bulletproof = false, rct::multisig_out *msout = NULL);
+  bool construct_tx_with_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, const crypto::secret_key &tx_key, const std::vector<crypto::secret_key> &additional_tx_keys, bool rct = false, rct::RangeProofType  range_proof_type = rct::RangeProofBorromean, rct::multisig_out *msout = NULL, bool shuffle_outs = true);
+  bool construct_tx_and_get_tx_key(const account_keys& sender_account_keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, std::vector<tx_source_entry>& sources, std::vector<tx_destination_entry>& destinations, const boost::optional<cryptonote::account_public_address>& change_addr, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, crypto::secret_key &tx_key, std::vector<crypto::secret_key> &additional_tx_keys, bool rct = false, rct::RangeProofType  range_proof_type = rct::RangeProofBorromean, rct::multisig_out *msout = NULL);
 
   bool generate_genesis_block(
       block& bl
diff --git a/src/ringct/rctSigs.cpp b/src/ringct/rctSigs.cpp
index cc966c44b..6dcb203bf 100644
--- a/src/ringct/rctSigs.cpp
+++ b/src/ringct/rctSigs.cpp
@@ -45,30 +45,6 @@ using namespace std;
 #define CHECK_AND_ASSERT_MES_L1(expr, ret, message) {if(!(expr)) {MCERROR("verify", message); return ret;}}
 
 namespace rct {
-    bool is_simple(int type)
-    {
-        switch (type)
-        {
-            case RCTTypeSimple:
-            case RCTTypeSimpleBulletproof:
-                return true;
-            default:
-                return false;
-        }
-    }
-
-    bool is_bulletproof(int type)
-    {
-        switch (type)
-        {
-            case RCTTypeSimpleBulletproof:
-            case RCTTypeFullBulletproof:
-                return true;
-            default:
-                return false;
-        }
-    }
-
     Bulletproof proveRangeBulletproof(key &C, key &mask, uint64_t amount)
     {
         mask = rct::skGen();
@@ -78,6 +54,15 @@ namespace rct {
         return proof;
     }
 
+    Bulletproof proveRangeBulletproof(keyV &C, keyV &masks, const std::vector<uint64_t> &amounts)
+    {
+        masks = rct::skvGen(amounts.size());
+        Bulletproof proof = bulletproof_PROVE(amounts, masks);
+        CHECK_AND_ASSERT_THROW_MES(proof.V.size() == amounts.size(), "V does not have the expected size");
+        C = proof.V;
+        return proof;
+    }
+
     bool verBulletproof(const Bulletproof &proof)
     {
       try { return bulletproof_VERIFY(proof); }
@@ -389,7 +374,7 @@ namespace rct {
       std::stringstream ss;
       binary_archive<true> ba(ss);
       CHECK_AND_ASSERT_THROW_MES(!rv.mixRing.empty(), "Empty mixRing");
-      const size_t inputs = is_simple(rv.type) ? rv.mixRing.size() : rv.mixRing[0].size();
+      const size_t inputs = is_rct_simple(rv.type) ? rv.mixRing.size() : rv.mixRing[0].size();
       const size_t outputs = rv.ecdhInfo.size();
       key prehash;
       CHECK_AND_ASSERT_THROW_MES(const_cast<rctSig&>(rv).serialize_rctsig_base(ba, inputs, outputs),
@@ -659,7 +644,8 @@ namespace rct {
     //   must know the destination private key to find the correct amount, else will return a random number
     //   Note: For txn fees, the last index in the amounts vector should contain that
     //   Thus the amounts vector will be "one" longer than the destinations vectort
-    rctSig genRct(const key &message, const ctkeyV & inSk, const keyV & destinations, const vector<xmr_amount> & amounts, const ctkeyM &mixRing, const keyV &amount_keys, const multisig_kLRki *kLRki, multisig_out *msout, unsigned int index, ctkeyV &outSk, bool bulletproof, hw::device &hwdev) {
+    rctSig genRct(const key &message, const ctkeyV & inSk, const keyV & destinations, const vector<xmr_amount> & amounts, const ctkeyM &mixRing, const keyV &amount_keys, const multisig_kLRki *kLRki, multisig_out *msout, unsigned int index, ctkeyV &outSk, RangeProofType range_proof_type, hw::device &hwdev) {
+        const bool bulletproof = range_proof_type != RangeProofBorromean;
         CHECK_AND_ASSERT_THROW_MES(amounts.size() == destinations.size() || amounts.size() == destinations.size() + 1, "Different number of amounts/destinations");
         CHECK_AND_ASSERT_THROW_MES(amount_keys.size() == destinations.size(), "Different number of amount_keys/destinations");
         CHECK_AND_ASSERT_THROW_MES(index < mixRing.size(), "Bad index into mixRing");
@@ -672,9 +658,7 @@ namespace rct {
         rv.type = bulletproof ? RCTTypeFullBulletproof : RCTTypeFull;
         rv.message = message;
         rv.outPk.resize(destinations.size());
-        if (bulletproof)
-          rv.p.bulletproofs.resize(destinations.size());
-        else
+        if (!bulletproof)
           rv.p.rangeSigs.resize(destinations.size());
         rv.ecdhInfo.resize(destinations.size());
 
@@ -684,18 +668,46 @@ namespace rct {
         for (i = 0; i < destinations.size(); i++) {
             //add destination to sig
             rv.outPk[i].dest = copy(destinations[i]);
-            //compute range proof
-            if (bulletproof)
-                rv.p.bulletproofs[i] = proveRangeBulletproof(rv.outPk[i].mask, outSk[i].mask, amounts[i]);
-            else
+            //compute range proof (bulletproofs are done later)
+            if (!bulletproof)
+            {
                 rv.p.rangeSigs[i] = proveRange(rv.outPk[i].mask, outSk[i].mask, amounts[i]);
             #ifdef DBG
-            if (bulletproof)
-                CHECK_AND_ASSERT_THROW_MES(verBulletproof(rv.p.bulletproofs[i]), "verBulletproof failed on newly created proof");
-            else
                 CHECK_AND_ASSERT_THROW_MES(verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]), "verRange failed on newly created proof");
             #endif
+            }
+        }
+
+        rv.p.bulletproofs.clear();
+        if (bulletproof)
+        {
+            std::vector<uint64_t> proof_amounts;
+            size_t amounts_proved = 0;
+            while (amounts_proved < amounts.size())
+            {
+                size_t batch_size = 1;
+                if (range_proof_type == RangeProofMultiOutputBulletproof)
+                  while (batch_size * 2 + amounts_proved <= amounts.size())
+                    batch_size *= 2;
+                rct::keyV C, masks;
+                std::vector<uint64_t> batch_amounts(batch_size);
+                for (i = 0; i < batch_size; ++i)
+                  batch_amounts[i] = amounts[i + amounts_proved];
+                rv.p.bulletproofs.push_back(proveRangeBulletproof(C, masks, batch_amounts));
+            #ifdef DBG
+                CHECK_AND_ASSERT_THROW_MES(verBulletproof(rv.p.bulletproofs.back()), "verBulletproof failed on newly created proof");
+            #endif
+                for (i = 0; i < batch_size; ++i)
+                {
+                  rv.outPk[i + amounts_proved].mask = C[i];
+                  outSk[i + amounts_proved].mask = masks[i];
+                }
+                amounts_proved += batch_size;
+            }
+        }
 
+        for (i = 0; i < outSk.size(); ++i)
+        {
             //mask amount and mask
             rv.ecdhInfo[i].mask = copy(outSk[i].mask);
             rv.ecdhInfo[i].amount = d2h(amounts[i]);
@@ -725,12 +737,13 @@ namespace rct {
         ctkeyM mixRing;
         ctkeyV outSk;
         tie(mixRing, index) = populateFromBlockchain(inPk, mixin);
-        return genRct(message, inSk, destinations, amounts, mixRing, amount_keys, kLRki, msout, index, outSk, false, hwdev);
+        return genRct(message, inSk, destinations, amounts, mixRing, amount_keys, kLRki, msout, index, outSk, RangeProofBorromean, hwdev);
     }
     
     //RCT simple    
     //for post-rct only
-    rctSig genRctSimple(const key &message, const ctkeyV & inSk, const keyV & destinations, const vector<xmr_amount> &inamounts, const vector<xmr_amount> &outamounts, xmr_amount txnFee, const ctkeyM & mixRing, const keyV &amount_keys, const std::vector<multisig_kLRki> *kLRki, multisig_out *msout, const std::vector<unsigned int> & index, ctkeyV &outSk, bool bulletproof, hw::device &hwdev) {
+    rctSig genRctSimple(const key &message, const ctkeyV & inSk, const keyV & destinations, const vector<xmr_amount> &inamounts, const vector<xmr_amount> &outamounts, xmr_amount txnFee, const ctkeyM & mixRing, const keyV &amount_keys, const std::vector<multisig_kLRki> *kLRki, multisig_out *msout, const std::vector<unsigned int> & index, ctkeyV &outSk, RangeProofType range_proof_type, hw::device &hwdev) {
+        const bool bulletproof = range_proof_type != RangeProofBorromean;
         CHECK_AND_ASSERT_THROW_MES(inamounts.size() > 0, "Empty inamounts");
         CHECK_AND_ASSERT_THROW_MES(inamounts.size() == inSk.size(), "Different number of inamounts/inSk");
         CHECK_AND_ASSERT_THROW_MES(outamounts.size() == destinations.size(), "Different number of amounts/destinations");
@@ -822,7 +835,7 @@ namespace rct {
           mixRing[i].resize(mixin+1);
           index[i] = populateFromBlockchainSimple(mixRing[i], inPk[i], mixin);
         }
-        return genRctSimple(message, inSk, destinations, inamounts, outamounts, txnFee, mixRing, amount_keys, kLRki, msout, index, outSk, false, hwdev);
+        return genRctSimple(message, inSk, destinations, inamounts, outamounts, txnFee, mixRing, amount_keys, kLRki, msout, index, outSk, RangeProofBorromean, hwdev);
     }
 
     //RingCT protocol
@@ -838,10 +851,11 @@ namespace rct {
     bool verRct(const rctSig & rv, bool semantics) {
         PERF_TIMER(verRct);
         CHECK_AND_ASSERT_MES(rv.type == RCTTypeFull || rv.type == RCTTypeFullBulletproof, false, "verRct called on non-full rctSig");
+        const bool bulletproof = is_rct_bulletproof(rv.type);
         if (semantics)
         {
-          if (rv.type == RCTTypeFullBulletproof)
-            CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.bulletproofs.size(), false, "Mismatched sizes of outPk and rv.p.bulletproofs");
+          if (bulletproof)
+            CHECK_AND_ASSERT_MES(rv.outPk.size() == n_bulletproof_amounts(rv.p.bulletproofs), false, "Mismatched sizes of outPk and bulletproofs");
           else
             CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.rangeSigs.size(), false, "Mismatched sizes of outPk and rv.p.rangeSigs");
           CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.ecdhInfo.size(), false, "Mismatched sizes of outPk and rv.ecdhInfo");
@@ -858,21 +872,19 @@ namespace rct {
           if (semantics) {
             tools::threadpool& tpool = tools::threadpool::getInstance();
             tools::threadpool::waiter waiter;
-            std::deque<bool> results(rv.outPk.size(), false);
+            std::deque<bool> results(bulletproof ? rv.p.bulletproofs.size() : rv.outPk.size(), false);
             DP("range proofs verified?");
-            for (size_t i = 0; i < rv.outPk.size(); i++) {
-              tpool.submit(&waiter, [&, i] {
-                if (rv.p.rangeSigs.empty())
-                  results[i] = verBulletproof(rv.p.bulletproofs[i]);
-                else
-                  results[i] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]);
-              }, true);
-            }
+            if (bulletproof)
+              for (size_t i = 0; i < rv.p.bulletproofs.size(); i++)
+                tpool.submit(&waiter, [&, i] { results[i] = verBulletproof(rv.p.bulletproofs[i]); });
+            else
+              for (size_t i = 0; i < rv.outPk.size(); i++)
+                tpool.submit(&waiter, [&, i] { results[i] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]); });
             waiter.wait(&tpool);
 
-            for (size_t i = 0; i < rv.outPk.size(); ++i) {
+            for (size_t i = 0; i < results.size(); ++i) {
               if (!results[i]) {
-                LOG_PRINT_L1("Range proof verified failed for output " << i);
+                LOG_PRINT_L1("Range proof verified failed for proof " << i);
                 return false;
               }
             }
@@ -912,11 +924,12 @@ namespace rct {
         PERF_TIMER(verRctSimple);
 
         CHECK_AND_ASSERT_MES(rv.type == RCTTypeSimple || rv.type == RCTTypeSimpleBulletproof, false, "verRctSimple called on non simple rctSig");
+        const bool bulletproof = is_rct_bulletproof(rv.type);
         if (semantics)
         {
-          if (rv.type == RCTTypeSimpleBulletproof)
+          if (bulletproof)
           {
-            CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.bulletproofs.size(), false, "Mismatched sizes of outPk and rv.p.bulletproofs");
+            CHECK_AND_ASSERT_MES(rv.outPk.size() == n_bulletproof_amounts(rv.p.bulletproofs), false, "Mismatched sizes of outPk and bulletproofs");
             CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.size() == rv.p.MGs.size(), false, "Mismatched sizes of rv.p.pseudoOuts and rv.p.MGs");
             CHECK_AND_ASSERT_MES(rv.pseudoOuts.empty(), false, "rv.pseudoOuts is not empty");
           }
@@ -931,7 +944,7 @@ namespace rct {
         else
         {
           // semantics check is early, and mixRing/MGs aren't resolved yet
-          if (rv.type == RCTTypeSimpleBulletproof)
+          if (bulletproof)
             CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.size() == rv.mixRing.size(), false, "Mismatched sizes of rv.p.pseudoOuts and mixRing");
           else
             CHECK_AND_ASSERT_MES(rv.pseudoOuts.size() == rv.mixRing.size(), false, "Mismatched sizes of rv.pseudoOuts and mixRing");
@@ -943,7 +956,7 @@ namespace rct {
         tools::threadpool& tpool = tools::threadpool::getInstance();
         tools::threadpool::waiter waiter;
 
-        const keyV &pseudoOuts = is_bulletproof(rv.type) ? rv.p.pseudoOuts : rv.pseudoOuts;
+        const keyV &pseudoOuts = bulletproof ? rv.p.pseudoOuts : rv.pseudoOuts;
 
         if (semantics) {
           key sumOutpks = identity();
@@ -967,20 +980,18 @@ namespace rct {
           }
 
           results.clear();
-          results.resize(rv.outPk.size());
-          for (size_t i = 0; i < rv.outPk.size(); i++) {
-            tpool.submit(&waiter, [&, i] {
-              if (rv.p.rangeSigs.empty())
-                results[i] = verBulletproof(rv.p.bulletproofs[i]);
-              else
-                results[i] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]);
-            }, true);
-          }
+          results.resize(bulletproof ? rv.p.bulletproofs.size() : rv.outPk.size());
+          if (bulletproof)
+            for (size_t i = 0; i < rv.p.bulletproofs.size(); i++)
+              tpool.submit(&waiter, [&, i] { results[i] = verBulletproof(rv.p.bulletproofs[i]); });
+          else
+            for (size_t i = 0; i < rv.p.rangeSigs.size(); i++)
+              tpool.submit(&waiter, [&, i] { results[i] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]); });
           waiter.wait(&tpool);
 
           for (size_t i = 0; i < results.size(); ++i) {
             if (!results[i]) {
-              LOG_PRINT_L1("Range proof verified failed for output " << i);
+              LOG_PRINT_L1("Range proof verified failed for proof " << i);
               return false;
             }
           }
diff --git a/src/ringct/rctSigs.h b/src/ringct/rctSigs.h
index 5a9b2dd44..9a66310c7 100644
--- a/src/ringct/rctSigs.h
+++ b/src/ringct/rctSigs.h
@@ -119,10 +119,10 @@ namespace rct {
     //decodeRct: (c.f. https://eprint.iacr.org/2015/1098 section 5.1.1)
     //   uses the attached ecdh info to find the amounts represented by each output commitment
     //   must know the destination private key to find the correct amount, else will return a random number
-    rctSig genRct(const key &message, const ctkeyV & inSk, const keyV & destinations, const std::vector<xmr_amount> & amounts, const ctkeyM &mixRing, const keyV &amount_keys, const multisig_kLRki *kLRki, multisig_out *msout, unsigned int index, ctkeyV &outSk, bool bulletproof, hw::device &hwdev);
+    rctSig genRct(const key &message, const ctkeyV & inSk, const keyV & destinations, const std::vector<xmr_amount> & amounts, const ctkeyM &mixRing, const keyV &amount_keys, const multisig_kLRki *kLRki, multisig_out *msout, unsigned int index, ctkeyV &outSk, RangeProofType range_proof_type, hw::device &hwdev);
     rctSig genRct(const key &message, const ctkeyV & inSk, const ctkeyV  & inPk, const keyV & destinations, const std::vector<xmr_amount> & amounts, const keyV &amount_keys, const multisig_kLRki *kLRki, multisig_out *msout, const int mixin, hw::device &hwdev);
     rctSig genRctSimple(const key & message, const ctkeyV & inSk, const ctkeyV & inPk, const keyV & destinations, const std::vector<xmr_amount> & inamounts, const std::vector<xmr_amount> & outamounts, const keyV &amount_keys, const std::vector<multisig_kLRki> *kLRki, multisig_out *msout, xmr_amount txnFee, unsigned int mixin, hw::device &hwdev);
-    rctSig genRctSimple(const key & message, const ctkeyV & inSk, const keyV & destinations, const std::vector<xmr_amount> & inamounts, const std::vector<xmr_amount> & outamounts, xmr_amount txnFee, const ctkeyM & mixRing, const keyV &amount_keys, const std::vector<multisig_kLRki> *kLRki, multisig_out *msout, const std::vector<unsigned int> & index, ctkeyV &outSk, bool bulletproof, hw::device &hwdev);
+    rctSig genRctSimple(const key & message, const ctkeyV & inSk, const keyV & destinations, const std::vector<xmr_amount> & inamounts, const std::vector<xmr_amount> & outamounts, xmr_amount txnFee, const ctkeyM & mixRing, const keyV &amount_keys, const std::vector<multisig_kLRki> *kLRki, multisig_out *msout, const std::vector<unsigned int> & index, ctkeyV &outSk, RangeProofType range_proof_type, hw::device &hwdev);
     bool verRct(const rctSig & rv, bool semantics);
     static inline bool verRct(const rctSig & rv) { return verRct(rv, true) && verRct(rv, false); }
     bool verRctSimple(const rctSig & rv, bool semantics);
diff --git a/src/ringct/rctTypes.cpp b/src/ringct/rctTypes.cpp
index 5650b3ba1..72ef75780 100644
--- a/src/ringct/rctTypes.cpp
+++ b/src/ringct/rctTypes.cpp
@@ -209,4 +209,36 @@ namespace rct {
         return vali;
     }
 
+    bool is_rct_simple(int type)
+    {
+        switch (type)
+        {
+            case RCTTypeSimple:
+            case RCTTypeSimpleBulletproof:
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    bool is_rct_bulletproof(int type)
+    {
+        switch (type)
+        {
+            case RCTTypeSimpleBulletproof:
+            case RCTTypeFullBulletproof:
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    size_t n_bulletproof_amounts(const std::vector<Bulletproof> &proofs)
+    {
+        size_t n = 0;
+        for (const Bulletproof &proof: proofs)
+            n += proof.V.size();
+        return n;
+    }
+
 }
diff --git a/src/ringct/rctTypes.h b/src/ringct/rctTypes.h
index 68f04b0f1..5574c7784 100644
--- a/src/ringct/rctTypes.h
+++ b/src/ringct/rctTypes.h
@@ -213,6 +213,8 @@ namespace rct {
       END_SERIALIZE()
     };
 
+    size_t n_bulletproof_amounts(const std::vector<Bulletproof> &proofs);
+
     //A container to hold all signatures necessary for RingCT
     // rangeSigs holds all the rangeproof data of a transaction
     // MG holds the MLSAG signature of a transaction
@@ -227,6 +229,7 @@ namespace rct {
       RCTTypeFullBulletproof = 3,
       RCTTypeSimpleBulletproof = 4,
     };
+    enum RangeProofType { RangeProofBorromean, RangeProofBulletproof, RangeProofMultiOutputBulletproof };
     struct rctSigBase {
         uint8_t type;
         key message;
@@ -310,15 +313,19 @@ namespace rct {
           {
             ar.tag("bp");
             ar.begin_array();
-            PREPARE_CUSTOM_VECTOR_SERIALIZATION(outputs, bulletproofs);
-            if (bulletproofs.size() != outputs)
+            uint32_t nbp = bulletproofs.size();
+            FIELD(nbp)
+            PREPARE_CUSTOM_VECTOR_SERIALIZATION(nbp, bulletproofs);
+            if (bulletproofs.size() > outputs)
               return false;
-            for (size_t i = 0; i < outputs; ++i)
+            for (size_t i = 0; i < nbp; ++i)
             {
               FIELDS(bulletproofs[i])
-              if (outputs - i > 1)
+              if (nbp - i > 1)
                 ar.delimit_array();
             }
+            if (n_bulletproof_amounts(bulletproofs) != outputs)
+              return false;
             ar.end_array();
           }
           else
@@ -519,6 +526,9 @@ namespace rct {
     //int[64] to uint long long
     xmr_amount b2d(bits amountb);
 
+    bool is_rct_simple(int type);
+    bool is_rct_bulletproof(int type);
+
     static inline const rct::key &pk2rct(const crypto::public_key &pk) { return (const rct::key&)pk; }
     static inline const rct::key &sk2rct(const crypto::secret_key &sk) { return (const rct::key&)sk; }
     static inline const rct::key &ki2rct(const crypto::key_image &ki) { return (const rct::key&)ki; }
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index a2e36706e..fdba6d84a 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -5268,10 +5268,18 @@ bool wallet2::sign_tx(unsigned_tx_set &exported_txs, std::vector<wallet2::pendin
     LOG_PRINT_L1(" " << (n+1) << ": " << sd.sources.size() << " inputs, ring size " << sd.sources[0].outputs.size());
     signed_txes.ptx.push_back(pending_tx());
     tools::wallet2::pending_tx &ptx = signed_txes.ptx.back();
+    rct::RangeProofType range_proof_type = rct::RangeProofBorromean;
+    if (sd.use_bulletproofs)
+    {
+      range_proof_type = rct::RangeProofBulletproof;
+      for (const rct::Bulletproof &proof: ptx.tx.rct_signatures.p.bulletproofs)
+        if (proof.V.size() > 1)
+          range_proof_type = rct::RangeProofMultiOutputBulletproof;
+    }
     crypto::secret_key tx_key;
     std::vector<crypto::secret_key> additional_tx_keys;
     rct::multisig_out msout;
-    bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sd.sources, sd.splitted_dsts, sd.change_dts.addr, sd.extra, ptx.tx, sd.unlock_time, tx_key, additional_tx_keys, sd.use_rct, sd.use_bulletproofs, m_multisig ? &msout : NULL);
+    bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sd.sources, sd.splitted_dsts, sd.change_dts.addr, sd.extra, ptx.tx, sd.unlock_time, tx_key, additional_tx_keys, sd.use_rct, range_proof_type, m_multisig ? &msout : NULL);
     THROW_WALLET_EXCEPTION_IF(!r, error::tx_not_constructed, sd.sources, sd.splitted_dsts, sd.unlock_time, m_nettype);
     // we don't test tx size, because we don't know the current limit, due to not having a blockchain,
     // and it's a bit pointless to fail there anyway, since it'd be a (good) guess only. We sign anyway,
@@ -5684,7 +5692,15 @@ bool wallet2::sign_multisig_tx(multisig_tx_set &exported_txs, std::vector<crypto
     cryptonote::transaction tx;
     rct::multisig_out msout = ptx.multisig_sigs.front().msout;
     auto sources = sd.sources;
-    bool r = cryptonote::construct_tx_with_tx_key(m_account.get_keys(), m_subaddresses, sources, sd.splitted_dsts, ptx.change_dts.addr, sd.extra, tx, sd.unlock_time, ptx.tx_key, ptx.additional_tx_keys, sd.use_rct, sd.use_bulletproofs, &msout, false);
+    rct::RangeProofType range_proof_type = rct::RangeProofBorromean;
+    if (sd.use_bulletproofs)
+    {
+      range_proof_type = rct::RangeProofBulletproof;
+      for (const rct::Bulletproof &proof: ptx.tx.rct_signatures.p.bulletproofs)
+        if (proof.V.size() > 1)
+          range_proof_type = rct::RangeProofMultiOutputBulletproof;
+    }
+    bool r = cryptonote::construct_tx_with_tx_key(m_account.get_keys(), m_subaddresses, sources, sd.splitted_dsts, ptx.change_dts.addr, sd.extra, tx, sd.unlock_time, ptx.tx_key, ptx.additional_tx_keys, sd.use_rct, range_proof_type, &msout, false);
     THROW_WALLET_EXCEPTION_IF(!r, error::tx_not_constructed, sd.sources, sd.splitted_dsts, sd.unlock_time, m_nettype);
 
     THROW_WALLET_EXCEPTION_IF(get_transaction_prefix_hash (tx) != get_transaction_prefix_hash(ptx.tx),
@@ -7054,7 +7070,7 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
   std::vector<crypto::secret_key> additional_tx_keys;
   rct::multisig_out msout;
   LOG_PRINT_L2("constructing tx");
-  bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sources, splitted_dsts, change_dts.addr, extra, tx, unlock_time, tx_key, additional_tx_keys, false, false, m_multisig ? &msout : NULL);
+  bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sources, splitted_dsts, change_dts.addr, extra, tx, unlock_time, tx_key, additional_tx_keys, false, rct::RangeProofBulletproof, m_multisig ? &msout : NULL);
   LOG_PRINT_L2("constructed tx, r="<<r);
   THROW_WALLET_EXCEPTION_IF(!r, error::tx_not_constructed, sources, splitted_dsts, unlock_time, m_nettype);
   THROW_WALLET_EXCEPTION_IF(upper_transaction_size_limit <= get_object_blobsize(tx), error::tx_too_big, tx, upper_transaction_size_limit);
@@ -7103,7 +7119,7 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
 
 void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry> dsts, const std::vector<size_t>& selected_transfers, size_t fake_outputs_count,
   std::vector<std::vector<tools::wallet2::get_outs_entry>> &outs,
-  uint64_t unlock_time, uint64_t fee, const std::vector<uint8_t>& extra, cryptonote::transaction& tx, pending_tx &ptx, bool bulletproof)
+  uint64_t unlock_time, uint64_t fee, const std::vector<uint8_t>& extra, cryptonote::transaction& tx, pending_tx &ptx, rct::RangeProofType range_proof_type)
 {
   using namespace cryptonote;
   // throw if attempting a transaction with no destinations
@@ -7259,7 +7275,7 @@ void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry
   rct::multisig_out msout;
   LOG_PRINT_L2("constructing tx");
   auto sources_copy = sources;
-  bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sources, splitted_dsts, change_dts.addr, extra, tx, unlock_time, tx_key, additional_tx_keys, true, bulletproof, m_multisig ? &msout : NULL);
+  bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sources, splitted_dsts, change_dts.addr, extra, tx, unlock_time, tx_key, additional_tx_keys, true, range_proof_type, m_multisig ? &msout : NULL);
   LOG_PRINT_L2("constructed tx, r="<<r);
   THROW_WALLET_EXCEPTION_IF(!r, error::tx_not_constructed, sources, dsts, unlock_time, m_nettype);
   THROW_WALLET_EXCEPTION_IF(upper_transaction_size_limit <= get_object_blobsize(tx), error::tx_too_big, tx, upper_transaction_size_limit);
@@ -7304,7 +7320,7 @@ void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry
         LOG_PRINT_L2("Creating supplementary multisig transaction");
         cryptonote::transaction ms_tx;
         auto sources_copy_copy = sources_copy;
-        bool r = cryptonote::construct_tx_with_tx_key(m_account.get_keys(), m_subaddresses, sources_copy_copy, splitted_dsts, change_dts.addr, extra, ms_tx, unlock_time,tx_key, additional_tx_keys, true, bulletproof, &msout, false);
+        bool r = cryptonote::construct_tx_with_tx_key(m_account.get_keys(), m_subaddresses, sources_copy_copy, splitted_dsts, change_dts.addr, extra, ms_tx, unlock_time,tx_key, additional_tx_keys, true, range_proof_type, &msout, false);
         LOG_PRINT_L2("constructed tx, r="<<r);
         THROW_WALLET_EXCEPTION_IF(!r, error::tx_not_constructed, sources, splitted_dsts, unlock_time, m_nettype);
         THROW_WALLET_EXCEPTION_IF(upper_transaction_size_limit <= get_object_blobsize(tx), error::tx_too_big, tx, upper_transaction_size_limit);
@@ -8010,6 +8026,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
   uint64_t upper_transaction_size_limit = get_upper_transaction_size_limit();
   const bool use_rct = use_fork_rules(4, 0);
   const bool bulletproof = use_fork_rules(get_bulletproof_fork(), 0);
+  const rct::RangeProofType range_proof_type = bulletproof ? rct::RangeProofMultiOutputBulletproof : rct::RangeProofBorromean;
 
   const uint64_t fee_per_kb  = get_per_kb_fee();
   const uint64_t fee_multiplier = get_fee_multiplier(priority, get_fee_algorithm());
@@ -8326,7 +8343,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
         tx.selected_transfers.size() << " inputs");
       if (use_rct)
         transfer_selected_rct(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
-          test_tx, test_ptx, bulletproof);
+          test_tx, test_ptx, range_proof_type);
       else
         transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
           detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
@@ -8369,7 +8386,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
         while (needed_fee > test_ptx.fee) {
           if (use_rct)
             transfer_selected_rct(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
-              test_tx, test_ptx, bulletproof);
+              test_tx, test_ptx, range_proof_type);
           else
             transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
               detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
@@ -8442,7 +8459,7 @@ skip_tx:
                             extra,                      /* const std::vector<uint8_t>& extra, */
                             test_tx,                    /* OUT   cryptonote::transaction& tx, */
                             test_ptx,                   /* OUT   cryptonote::transaction& tx, */
-                            bulletproof);
+                            range_proof_type);
     } else {
       transfer_selected(tx.dsts,
                         tx.selected_transfers,
@@ -8581,6 +8598,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
 
   const bool use_rct = fake_outs_count > 0 && use_fork_rules(4, 0);
   const bool bulletproof = use_fork_rules(get_bulletproof_fork(), 0);
+  const rct::RangeProofType range_proof_type = bulletproof ? rct::RangeProofBulletproof : rct::RangeProofBorromean;
   const uint64_t fee_per_kb  = get_per_kb_fee();
   const uint64_t fee_multiplier = get_fee_multiplier(priority, get_fee_algorithm());
 
@@ -8636,7 +8654,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
         tx.selected_transfers.size() << " outputs");
       if (use_rct)
         transfer_selected_rct(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
-          test_tx, test_ptx, bulletproof);
+          test_tx, test_ptx, range_proof_type);
       else
         transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
           detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
@@ -8653,7 +8671,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
         tx.dsts[0].amount = available_for_fee - needed_fee;
         if (use_rct)
           transfer_selected_rct(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra, 
-            test_tx, test_ptx, bulletproof);
+            test_tx, test_ptx, range_proof_type);
         else
           transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
             detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
@@ -8692,7 +8710,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
     pending_tx test_ptx;
     if (use_rct) {
       transfer_selected_rct(tx.dsts, tx.selected_transfers, fake_outs_count, tx.outs, unlock_time, tx.needed_fee, extra,
-        test_tx, test_ptx, bulletproof);
+        test_tx, test_ptx, range_proof_type);
     } else {
       transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, tx.outs, unlock_time, tx.needed_fee, extra,
         detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 556679f51..3ba51a27c 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -729,7 +729,7 @@ namespace tools
       uint64_t unlock_time, uint64_t fee, const std::vector<uint8_t>& extra, T destination_split_strategy, const tx_dust_policy& dust_policy, cryptonote::transaction& tx, pending_tx &ptx);
     void transfer_selected_rct(std::vector<cryptonote::tx_destination_entry> dsts, const std::vector<size_t>& selected_transfers, size_t fake_outputs_count,
       std::vector<std::vector<tools::wallet2::get_outs_entry>> &outs,
-      uint64_t unlock_time, uint64_t fee, const std::vector<uint8_t>& extra, cryptonote::transaction& tx, pending_tx &ptx, bool bulletproof);
+      uint64_t unlock_time, uint64_t fee, const std::vector<uint8_t>& extra, cryptonote::transaction& tx, pending_tx &ptx, rct::RangeProofType range_proof_type);
 
     void commit_tx(pending_tx& ptx_vector);
     void commit_tx(std::vector<pending_tx>& ptx_vector);
@@ -1968,7 +1968,7 @@ namespace tools
     crypto::secret_key tx_key;
     std::vector<crypto::secret_key> additional_tx_keys;
     rct::multisig_out msout;
-    bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sources, splitted_dsts, change_dts.addr, extra, tx, unlock_time, tx_key, additional_tx_keys, false, false, m_multisig ? &msout : NULL);
+    bool r = cryptonote::construct_tx_and_get_tx_key(m_account.get_keys(), m_subaddresses, sources, splitted_dsts, change_dts.addr, extra, tx, unlock_time, tx_key, additional_tx_keys, false, rct::RangeProofBorromean, m_multisig ? &msout : NULL);
     THROW_WALLET_EXCEPTION_IF(!r, error::tx_not_constructed, sources, splitted_dsts, unlock_time, m_nettype);
     THROW_WALLET_EXCEPTION_IF(upper_transaction_size_limit <= get_object_blobsize(tx), error::tx_too_big, tx, upper_transaction_size_limit);