diff --git a/src/chain.h b/src/chain.h
index 52f4e06a41..deecf2d527 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -1,543 +1,554 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_CHAIN_H
 #define BITCOIN_CHAIN_H
 
 #include "arith_uint256.h"
 #include "consensus/params.h"
 #include "pow.h"
 #include "primitives/block.h"
 #include "tinyformat.h"
 #include "uint256.h"
 
 #include <unordered_map>
 #include <vector>
 
 /**
  * Maximum amount of time that a block timestamp is allowed to exceed the
  * current network-adjusted time before the block will be accepted.
  */
 static const int64_t MAX_FUTURE_BLOCK_TIME = 2 * 60 * 60;
 
 /**
  * Timestamp window used as a grace period by code that compares external
  * timestamps (such as timestamps passed to RPCs, or wallet key creation times)
  * to block timestamps. This should be set at least as high as
  * MAX_FUTURE_BLOCK_TIME.
  */
 static const int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
 
 class CBlockFileInfo {
 public:
     //!< number of blocks stored in file
     unsigned int nBlocks;
     //!< number of used bytes of block file
     unsigned int nSize;
     //!< number of used bytes in the undo file
     unsigned int nUndoSize;
     //!< lowest height of block in file
     unsigned int nHeightFirst;
     //!< highest height of block in file
     unsigned int nHeightLast;
     //!< earliest time of block in file
     uint64_t nTimeFirst;
     //!< latest time of block in file
     uint64_t nTimeLast;
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(VARINT(nBlocks));
         READWRITE(VARINT(nSize));
         READWRITE(VARINT(nUndoSize));
         READWRITE(VARINT(nHeightFirst));
         READWRITE(VARINT(nHeightLast));
         READWRITE(VARINT(nTimeFirst));
         READWRITE(VARINT(nTimeLast));
     }
 
     void SetNull() {
         nBlocks = 0;
         nSize = 0;
         nUndoSize = 0;
         nHeightFirst = 0;
         nHeightLast = 0;
         nTimeFirst = 0;
         nTimeLast = 0;
     }
 
     CBlockFileInfo() { SetNull(); }
 
     std::string ToString() const;
 
     /** update statistics (does not update nSize) */
     void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn) {
         if (nBlocks == 0 || nHeightFirst > nHeightIn) {
             nHeightFirst = nHeightIn;
         }
         if (nBlocks == 0 || nTimeFirst > nTimeIn) {
             nTimeFirst = nTimeIn;
         }
         nBlocks++;
         if (nHeightIn > nHeightLast) {
             nHeightLast = nHeightIn;
         }
         if (nTimeIn > nTimeLast) {
             nTimeLast = nTimeIn;
         }
     }
 };
 
 struct CDiskBlockPos {
     int nFile;
     unsigned int nPos;
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(VARINT(nFile));
         READWRITE(VARINT(nPos));
     }
 
     CDiskBlockPos() { SetNull(); }
 
     CDiskBlockPos(int nFileIn, unsigned int nPosIn) {
         nFile = nFileIn;
         nPos = nPosIn;
     }
 
     friend bool operator==(const CDiskBlockPos &a, const CDiskBlockPos &b) {
         return (a.nFile == b.nFile && a.nPos == b.nPos);
     }
 
     friend bool operator!=(const CDiskBlockPos &a, const CDiskBlockPos &b) {
         return !(a == b);
     }
 
     void SetNull() {
         nFile = -1;
         nPos = 0;
     }
     bool IsNull() const { return (nFile == -1); }
 
     std::string ToString() const {
         return strprintf("CBlockDiskPos(nFile=%i, nPos=%i)", nFile, nPos);
     }
 };
 
 enum BlockStatus : uint32_t {
     //! Unused.
     BLOCK_VALID_UNKNOWN = 0,
 
     //! Parsed, version ok, hash satisfies claimed PoW, 1 <= vtx count <= max,
     //! timestamp not in future
     BLOCK_VALID_HEADER = 1,
 
     //! All parent headers found, difficulty matches, timestamp >= median
     //! previous, checkpoint. Implies all parents are also at least TREE.
     BLOCK_VALID_TREE = 2,
 
     /**
      * Only first tx is coinbase, 2 <= coinbase input script length <= 100,
      * transactions valid, no duplicate txids, sigops, size, merkle root.
      * Implies all parents are at least TREE but not necessarily TRANSACTIONS.
      * When all parent blocks also have TRANSACTIONS, CBlockIndex::nChainTx will
      * be set.
      */
     BLOCK_VALID_TRANSACTIONS = 3,
 
     //! Outputs do not overspend inputs, no double spends, coinbase output ok,
     //! no immature coinbase spends, BIP30.
     //! Implies all parents are also at least CHAIN.
     BLOCK_VALID_CHAIN = 4,
 
     //! Scripts & signatures ok. Implies all parents are also at least SCRIPTS.
     BLOCK_VALID_SCRIPTS = 5,
 
     //! All validity bits.
     BLOCK_VALID_MASK = BLOCK_VALID_HEADER | BLOCK_VALID_TREE |
                        BLOCK_VALID_TRANSACTIONS | BLOCK_VALID_CHAIN |
                        BLOCK_VALID_SCRIPTS,
 
     //!< full block available in blk*.dat
     BLOCK_HAVE_DATA = 8,
     //!< undo data available in rev*.dat
     BLOCK_HAVE_UNDO = 16,
     BLOCK_HAVE_MASK = BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO,
 
     //!< stage after last reached validness failed
     BLOCK_FAILED_VALID = 32,
     //!< descends from failed block
     BLOCK_FAILED_CHILD = 64,
     BLOCK_FAILED_MASK = BLOCK_FAILED_VALID | BLOCK_FAILED_CHILD,
 };
 
 /**
  * The block chain is a tree shaped structure starting with the genesis block at
  * the root, with each block potentially having multiple candidates to be the
  * next block. A blockindex may have multiple pprev pointing to it, but at most
  * one of them can be part of the currently active branch.
  */
 class CBlockIndex {
 public:
     //! pointer to the hash of the block, if any. Memory is owned by this
     //! CBlockIndex
     const uint256 *phashBlock;
 
     //! pointer to the index of the predecessor of this block
     CBlockIndex *pprev;
 
     //! pointer to the index of some further predecessor of this block
     CBlockIndex *pskip;
 
     //! height of the entry in the chain. The genesis block has height 0
     int nHeight;
 
     //! Which # file this block is stored in (blk?????.dat)
     int nFile;
 
     //! Byte offset within blk?????.dat where this block's data is stored
     unsigned int nDataPos;
 
     //! Byte offset within rev?????.dat where this block's undo data is stored
     unsigned int nUndoPos;
 
     //! (memory only) Total amount of work (expected number of hashes) in the
     //! chain up to and including this block
     arith_uint256 nChainWork;
 
     //! Number of transactions in this block.
     //! Note: in a potential headers-first mode, this number cannot be relied
     //! upon
     unsigned int nTx;
 
     //! (memory only) Number of transactions in the chain up to and including
     //! this block.
     //! This value will be non-zero only if and only if transactions for this
     //! block and all its parents are available. Change to 64-bit type when
     //! necessary; won't happen before 2030
     unsigned int nChainTx;
 
     //! Verification status of this block. See enum BlockStatus
     uint32_t nStatus;
 
     //! block header
     int32_t nVersion;
     uint256 hashMerkleRoot;
     uint32_t nTime;
     uint32_t nBits;
     uint32_t nNonce;
 
     //! (memory only) Sequential id assigned to distinguish order in which
     //! blocks are received.
     int32_t nSequenceId;
 
+    //! (memory only) block header metadata
+    uint64_t nTimeReceived;
+
     //! (memory only) Maximum nTime in the chain upto and including this block.
     unsigned int nTimeMax;
 
     void SetNull() {
         phashBlock = nullptr;
         pprev = nullptr;
         pskip = nullptr;
         nHeight = 0;
         nFile = 0;
         nDataPos = 0;
         nUndoPos = 0;
         nChainWork = arith_uint256();
         nTx = 0;
         nChainTx = 0;
         nStatus = 0;
         nSequenceId = 0;
         nTimeMax = 0;
 
         nVersion = 0;
         hashMerkleRoot = uint256();
         nTime = 0;
+        nTimeReceived = 0;
         nBits = 0;
         nNonce = 0;
     }
 
     CBlockIndex() { SetNull(); }
 
     CBlockIndex(const CBlockHeader &block) {
         SetNull();
 
         nVersion = block.nVersion;
         hashMerkleRoot = block.hashMerkleRoot;
         nTime = block.nTime;
+        // Default to block time if nTimeReceived is never set, which
+        // in effect assumes that this block is honestly mined.
+        // Note that nTimeReceived isn't written to disk, so blocks read from
+        // disk will be assumed to be honestly mined.
+        nTimeReceived = block.nTime;
         nBits = block.nBits;
         nNonce = block.nNonce;
     }
 
     CDiskBlockPos GetBlockPos() const {
         CDiskBlockPos ret;
         if (nStatus & BLOCK_HAVE_DATA) {
             ret.nFile = nFile;
             ret.nPos = nDataPos;
         }
         return ret;
     }
 
     CDiskBlockPos GetUndoPos() const {
         CDiskBlockPos ret;
         if (nStatus & BLOCK_HAVE_UNDO) {
             ret.nFile = nFile;
             ret.nPos = nUndoPos;
         }
         return ret;
     }
 
     CBlockHeader GetBlockHeader() const {
         CBlockHeader block;
         block.nVersion = nVersion;
         if (pprev) {
             block.hashPrevBlock = pprev->GetBlockHash();
         }
         block.hashMerkleRoot = hashMerkleRoot;
         block.nTime = nTime;
         block.nBits = nBits;
         block.nNonce = nNonce;
         return block;
     }
 
     uint256 GetBlockHash() const { return *phashBlock; }
 
     int64_t GetBlockTime() const { return int64_t(nTime); }
 
     int64_t GetBlockTimeMax() const { return int64_t(nTimeMax); }
 
+    int64_t GetHeaderTimeReceived() const { return nTimeReceived; }
+
     enum { nMedianTimeSpan = 11 };
 
     int64_t GetMedianTimePast() const {
         int64_t pmedian[nMedianTimeSpan];
         int64_t *pbegin = &pmedian[nMedianTimeSpan];
         int64_t *pend = &pmedian[nMedianTimeSpan];
 
         const CBlockIndex *pindex = this;
         for (int i = 0; i < nMedianTimeSpan && pindex;
              i++, pindex = pindex->pprev) {
             *(--pbegin) = pindex->GetBlockTime();
         }
 
         std::sort(pbegin, pend);
         return pbegin[(pend - pbegin) / 2];
     }
 
     std::string ToString() const {
         return strprintf(
             "CBlockIndex(pprev=%p, nHeight=%d, merkle=%s, hashBlock=%s)", pprev,
             nHeight, hashMerkleRoot.ToString(), GetBlockHash().ToString());
     }
 
     //! Check whether this block index entry is valid up to the passed validity
     //! level.
     bool IsValid(enum BlockStatus nUpTo = BLOCK_VALID_TRANSACTIONS) const {
         // Only validity flags allowed.
         assert(!(nUpTo & ~BLOCK_VALID_MASK));
         if (nStatus & BLOCK_FAILED_MASK) {
             return false;
         }
         return ((nStatus & BLOCK_VALID_MASK) >= nUpTo);
     }
 
     //! Raise the validity level of this block index entry.
     //! Returns true if the validity was changed.
     bool RaiseValidity(enum BlockStatus nUpTo) {
         // Only validity flags allowed.
         assert(!(nUpTo & ~BLOCK_VALID_MASK));
         if (nStatus & BLOCK_FAILED_MASK) {
             return false;
         }
         if ((nStatus & BLOCK_VALID_MASK) < nUpTo) {
             nStatus = (nStatus & ~BLOCK_VALID_MASK) | nUpTo;
             return true;
         }
         return false;
     }
 
     //! Build the skiplist pointer for this entry.
     void BuildSkip();
 
     //! Efficiently find an ancestor of this block.
     CBlockIndex *GetAncestor(int height);
     const CBlockIndex *GetAncestor(int height) const;
 };
 
 /**
  * Maintain a map of CBlockIndex for all known headers.
  */
 struct BlockHasher {
     size_t operator()(const uint256 &hash) const { return hash.GetCheapHash(); }
 };
 
 typedef std::unordered_map<uint256, CBlockIndex *, BlockHasher> BlockMap;
 extern BlockMap mapBlockIndex;
 
 arith_uint256 GetBlockProof(const CBlockIndex &block);
 
 /**
  * Return the time it would take to redo the work difference between from and
  * to, assuming the current hashrate corresponds to the difficulty at tip, in
  * seconds.
  */
 int64_t GetBlockProofEquivalentTime(const CBlockIndex &to,
                                     const CBlockIndex &from,
                                     const CBlockIndex &tip,
                                     const Consensus::Params &);
 /**
  * Find the forking point between two chain tips.
  */
 const CBlockIndex *LastCommonAncestor(const CBlockIndex *pa,
                                       const CBlockIndex *pb);
 
 /** Used to marshal pointers into hashes for db storage. */
 class CDiskBlockIndex : public CBlockIndex {
 public:
     uint256 hashPrev;
 
     CDiskBlockIndex() { hashPrev = uint256(); }
 
     explicit CDiskBlockIndex(const CBlockIndex *pindex) : CBlockIndex(*pindex) {
         hashPrev = (pprev ? pprev->GetBlockHash() : uint256());
     }
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             READWRITE(VARINT(nVersion));
         }
 
         READWRITE(VARINT(nHeight));
         READWRITE(VARINT(nStatus));
         READWRITE(VARINT(nTx));
         if (nStatus & (BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO)) {
             READWRITE(VARINT(nFile));
         }
         if (nStatus & BLOCK_HAVE_DATA) {
             READWRITE(VARINT(nDataPos));
         }
         if (nStatus & BLOCK_HAVE_UNDO) {
             READWRITE(VARINT(nUndoPos));
         }
 
         // block header
         READWRITE(this->nVersion);
         READWRITE(hashPrev);
         READWRITE(hashMerkleRoot);
         READWRITE(nTime);
         READWRITE(nBits);
         READWRITE(nNonce);
     }
 
     uint256 GetBlockHash() const {
         CBlockHeader block;
         block.nVersion = nVersion;
         block.hashPrevBlock = hashPrev;
         block.hashMerkleRoot = hashMerkleRoot;
         block.nTime = nTime;
         block.nBits = nBits;
         block.nNonce = nNonce;
         return block.GetHash();
     }
 
     std::string ToString() const {
         std::string str = "CDiskBlockIndex(";
         str += CBlockIndex::ToString();
         str += strprintf("\n                hashBlock=%s, hashPrev=%s)",
                          GetBlockHash().ToString(), hashPrev.ToString());
         return str;
     }
 };
 
 /**
  * An in-memory indexed chain of blocks.
  */
 class CChain {
 private:
     std::vector<CBlockIndex *> vChain;
 
 public:
     /**
      * Returns the index entry for the genesis block of this chain, or nullptr
      * if none.
      */
     CBlockIndex *Genesis() const {
         return vChain.size() > 0 ? vChain[0] : nullptr;
     }
 
     /**
      * Returns the index entry for the tip of this chain, or nullptr if none.
      */
     CBlockIndex *Tip() const {
         return vChain.size() > 0 ? vChain[vChain.size() - 1] : nullptr;
     }
 
     /**
      * Returns the index entry at a particular height in this chain, or nullptr
      * if no such height exists.
      */
     CBlockIndex *operator[](int nHeight) const {
         if (nHeight < 0 || nHeight >= (int)vChain.size()) {
             return nullptr;
         }
         return vChain[nHeight];
     }
 
     /** Compare two chains efficiently. */
     friend bool operator==(const CChain &a, const CChain &b) {
         return a.vChain.size() == b.vChain.size() &&
                a.vChain[a.vChain.size() - 1] == b.vChain[b.vChain.size() - 1];
     }
 
     /** Efficiently check whether a block is present in this chain. */
     bool Contains(const CBlockIndex *pindex) const {
         return (*this)[pindex->nHeight] == pindex;
     }
 
     /**
      * Find the successor of a block in this chain, or nullptr if the given
      * index is not found or is the tip.
      */
     CBlockIndex *Next(const CBlockIndex *pindex) const {
         if (!Contains(pindex)) {
             return nullptr;
         }
 
         return (*this)[pindex->nHeight + 1];
     }
 
     /**
      * Return the maximal height in the chain. Is equal to chain.Tip() ?
      * chain.Tip()->nHeight : -1.
      */
     int Height() const { return vChain.size() - 1; }
 
     /** Set/initialize a chain with a given tip. */
     void SetTip(CBlockIndex *pindex);
 
     /**
      * Return a CBlockLocator that refers to a block in this chain (by default
      * the tip).
      */
     CBlockLocator GetLocator(const CBlockIndex *pindex = nullptr) const;
 
     /**
      * Find the last common block between this chain and a block index entry.
      */
     const CBlockIndex *FindFork(const CBlockIndex *pindex) const;
 
     /**
      * Find the earliest block with timestamp equal or greater than the given.
      */
     CBlockIndex *FindEarliestAtLeast(int64_t nTime) const;
 };
 
 #endif // BITCOIN_CHAIN_H