return nSubsidy;
}
-static const int64 nTargetTimespan = 7 * 24 * 60 * 60; // one week
-static const int64 nTargetSpacing = 10 * 60;
-static const int64 nInterval = nTargetTimespan / nTargetSpacing;
-static const int64 nMaxClockDrift = 2 * 60 * 60; // 2 hours
+static const int64 nTargetTimespan = 7 * 24 * 60 * 60; // one week
+static const int64 nTargetSpacingStake = 10 * 60; // ten minutes
+static const int64 nTargetSpacingWorkMax = 2 * 60 * 60; // two hours
+static const int64 nMaxClockDrift = 2 * 60 * 60; // two hours
//
// minimum amount of work that could possibly be required nTime after
// ppcoin: retarget with exponential moving toward target spacing
CBigNum bnNew;
bnNew.SetCompact(pindexPrev->nBits);
+ int64 nTargetSpacing = fProofOfStake? nTargetSpacingStake : min(nTargetSpacingWorkMax, nTargetSpacingStake * (1 + pindexLast->nHeight - pindexPrev->nHeight));
+ int64 nInterval = nTargetTimespan / nTargetSpacing;
bnNew *= ((nInterval - 1) * nTargetSpacing + nActualSpacing + nActualSpacing);
bnNew /= ((nInterval + 1) * nTargetSpacing);
if (hashMerkleRoot != BuildMerkleTree())
return DoS(100, error("CheckBlock() : hashMerkleRoot mismatch"));
- // Coin base vout[0] scriptPubKey must be the same as coin stake vout[1]
- // scriptPubKey
- if (vtx.size() > 1 && vtx[1].IsCoinStake() &&
- vtx[0].vout[0].scriptPubKey != vtx[1].vout[1].scriptPubKey)
- return DoS(100, error("CheckBlock() : block key mismatch"));
-
-
- // Check block signature
+ // ppcoin: check block signature
if (!CheckBlockSignature())
return DoS(100, error("CheckBlock() : bad block signature"));
return error("ProcessBlock() : already have block (orphan) %s", hash.ToString().substr(0,20).c_str());
// ppcoin: check proof-of-stake
- if (pblock->IsProofOfStake() && setStakeSeen.count(pblock->GetProofOfStake()))
+ // Limited duplicity on stake: prevents block flood attack
+ // Duplicate stake allowed only when there is orphan child block
+ if (pblock->IsProofOfStake() && setStakeSeen.count(pblock->GetProofOfStake()) && !mapOrphanBlocksByPrev.count(hash))
return error("ProcessBlock() : duplicate proof-of-stake (%s) for block %s", pblock->GetProofOfStake().ToString().c_str(), hash.ToString().c_str());
// Preliminary checks
// ppcoin: check proof-of-stake
if (pblock2->IsProofOfStake())
{
- if (setStakeSeenOrphan.count(pblock2->GetProofOfStake()))
+ // Limited duplicity on stake: prevents block flood attack
+ // Duplicate stake allowed only when there is orphan child block
+ if (setStakeSeenOrphan.count(pblock2->GetProofOfStake()) && !mapOrphanBlocksByPrev.count(hash))
return error("ProcessBlock() : duplicate proof-of-stake (%s) for orphan block %s", pblock2->GetProofOfStake().ToString().c_str(), hash.ToString().c_str());
else
setStakeSeenOrphan.insert(pblock2->GetProofOfStake());
}
}
}
- pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
+ if (pblock->IsProofOfWork())
+ pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
// Fill in header
pblock->hashPrevBlock = pindexPrev->GetBlockHash();