[ANN] Blacknet BLN | Staking | Future of zApp & ZeFi

[delion19]

@rat4, @seopkip

ComputeNextStakeModifier uses hashes of 64 blocks (both PoW and PoS) as source of entropy.
Compare 64 blocks to forge StakeModifier with 10 blocks to confirm transaction.

Read this thread more closely: https://bitcointalk.org/index.php?topic=131901.0

And diff PPCoin 0.2 and 0.3

You'll see why it's a bad idea to turn off PoW

Have you read this post? And have there been any counter measures taken work around the problem?

[colinfx]

Oh wow, that BC Multipool sounds pretty neat, count me in for hopping in to the beta. I wish I had more for donations, but my stack is pretty thin.

You can see the site here: http://bcmultipool.com/

Announcement is later this evening

[colinfx]

Concrete 1000, now we go to 1500, proposes to put a wall in 1000 it will deter day traders

It looks like bots are picking up all orders at 1,000-1,050 - someone is accumulating cheap blackcoin...

Supply will dry up further once http://bcmultipool.com/ starts running, this must be a first for an alt right??

[MuffinMaster]

Concrete 1000, now we go to 1500, proposes to put a wall in 1000 it will deter day traders

Not many coins being sold under 1100, ask is well over that. Mostly quiet for now as people accumulate for the next leg.

[StolenCoinSalesman]

Oh wow, that BC Multipool sounds pretty neat, count me in for hopping in to the beta. I wish I had more for donations, but my stack is pretty thin.

You can see the site here: http://bcmultipool.com/

Announcement is later this evening

I CANT WAIT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:o

[tacotime]

Have you read this post? And have there been any counter measures taken work around the problem?

I don't think there's any easy fix not including PoW, and if you make the chain completely PoS you run into the forking issue (that miners can mine both forks of a chain easily and without consequence, so when forks are started they continue to propagate forever).

You can just turn PoW back on and make the block reward 0 at block 10,000.

[brokedummy]

Just got an idea on the POS.. does this mean that i am only earning 1% of my total coins every year?

for example a coins worth 1,000 USD will have an interest of 10 USD per year? and the wallet should be left unlock and let it go POS mining?

if that's the case it's a very low profit on holding the coins for a long period of time.. or maybe my understanding is incorrect.
please enlighten me.

The 1% per year means the coin price only needs to rise 1% per year in order for your investment to not lose value. Compare with MINT, the price will have to rise 20% in first year for holders to break even due to higher coin inflation.

1% per annum coin inflation is a big positive feature of BlackCoin. There is no huge new supply of coins to be dumped. If someone wants the coins, they have to buy them at market rate.

Why would the price have to rise for me to break even? Math is hard, but the way I see it, the price of Mint can go down 20% and since I will have 20% more Mint after a year I will still breakeven after a 20% price drop. Why are you are saying the price needs to rise 20% for me to breakeven?

[colinfx]

Just got an idea on the POS.. does this mean that i am only earning 1% of my total coins every year?

for example a coins worth 1,000 USD will have an interest of 10 USD per year? and the wallet should be left unlock and let it go POS mining?

if that's the case it's a very low profit on holding the coins for a long period of time.. or maybe my understanding is incorrect.
please enlighten me.

The 1% per year means the coin price only needs to rise 1% per year in order for your investment to not lose value. Compare with MINT, the price will have to rise 20% in first year for holders to break even due to higher coin inflation.

1% per annum coin inflation is a big positive feature of BlackCoin. There is no huge new supply of coins to be dumped. If someone wants the coins, they have to buy them at market rate.

Why would the price have to rise for me to break even? Math is hard, but the way I see it, the price of Mint can go down 20% and since I will have 20% more Mint after a year I will still breakeven after a 20% price drop. Why are you are saying the price needs to rise 20% for me to breakeven?

To keep same coin price a 20% inflationary coin has to rise by 20% otherwise the coin price drops. It is due to new coins being added to the supply. A coin with 1% inflation does not have this problem, only on a very tiny scale. If everyone always holds their coins it makes no difference. If everyone dumps their extra coins the price gets diluted downwards.

[colinfx]

Have you read this post? And have there been any counter measures taken work around the problem?

I don't think there's any easy fix not including PoW, and if you make the chain completely PoS you run into the forking issue (that miners can mine both forks of a chain easily and without consequence, so when forks are started they continue to propagate forever).

You can just turn PoW back on and make the block reward 0 at block 10,000.

That's seems sensible. Turn POW back on and set low/zero coin reward.

[delion19]

Have you read this post? And have there been any counter measures taken work around the problem?

I don't think there's any easy fix not including PoW, and if you make the chain completely PoS you run into the forking issue (that miners can mine both forks of a chain easily and without consequence, so when forks are started they continue to propagate forever).

You can just turn PoW back on and make the block reward 0 at block 10,000.

Ok, that makes sense from what I've read from the post. Haven't has a look at the code yet though so I haven't messed around with it myself. Truly a difficult problem to find a permanent fix for while remaining PoS only. What of the reported work-around by Sunny King, the PPC developer? Has he made it available? And moreso, does it work as intended?

[tacotime]

Ok, that makes sense from what I've read from the post. Haven't has a look at the code yet though so I haven't messed around with it myself. Truly a difficult problem to find a permanent fix for while remaining PoS only. What of the reported work-around by Sunny King, the PPC developer? Has he made it available? And moreso, does it work as intended?

Sunny King's workaround was to compute the modifier using PoW blocks for entropy so you'd couldn't game them by rapidly computing PoS blocks (as far as I could tell)

And to prevent the forking issue (although not a huge problem with the current state of PoW), he centralized the blockchain by constantly signing new checkpoints into the network.  This allows him to select which chain he thinks is the valid one, and then miners mine off of that.

[IconicExpert]

Just got an idea on the POS.. does this mean that i am only earning 1% of my total coins every year?

for example a coins worth 1,000 USD will have an interest of 10 USD per year? and the wallet should be left unlock and let it go POS mining?

if that's the case it's a very low profit on holding the coins for a long period of time.. or maybe my understanding is incorrect.
please enlighten me.

The 1% per year means the coin price only needs to rise 1% per year in order for your investment to not lose value. Compare with MINT, the price will have to rise 20% in first year for holders to break even due to higher coin inflation.

1% per annum coin inflation is a big positive feature of BlackCoin. There is no huge new supply of coins to be dumped. If someone wants the coins, they have to buy them at market rate.

Why would the price have to rise for me to break even? Math is hard, but the way I see it, the price of Mint can go down 20% and since I will have 20% more Mint after a year I will still breakeven after a 20% price drop. Why are you are saying the price needs to rise 20% for me to breakeven?

To keep same coin price a 20% inflationary coin has to rise by 20% otherwise the coin price drops. It is due to new coins being added to the supply. A coin with 1% inflation does not have this problem, only on a very tiny scale. If everyone always holds their coins it makes no difference. If everyone dumps their extra coins the price gets diluted downwards.

Colinfx well put. Too many people who mine and trade cryptocoins have a limited understanding of economics and inflation.

[delion19]

Ok, that makes sense from what I've read from the post. Haven't has a look at the code yet though so I haven't messed around with it myself. Truly a difficult problem to find a permanent fix for while remaining PoS only. What of the reported work-around by Sunny King, the PPC developer? Has he made it available? And moreso, does it work as intended?

Sunny King's workaround was to compute the modifier using PoW blocks for entropy so you'd couldn't game them by rapidly computing PoS blocks (as far as I could tell)

And to prevent the forking issue (although not a huge problem with the current state of PoW), he centralized the blockchain by constantly signing new checkpoints into the network.  This allows him to select which chain he thinks is the valid one, and then miners mine off of that.

OK. Seems like it requires significant manual maintenance and monitoring though.

[rat4]

Read this thread more closely: https://bitcointalk.org/index.php?topic=131901.0

And diff PPCoin 0.2 and 0.3

You'll see why it's a bad idea to turn off PoW

If I understand this correctly, there was additiotal search space caused by insufficient timestamp check and difficulty retarget every block. Both have nothing to do with PoW.

I don't think there's any easy fix not including PoW, and if you make the chain completely PoS you run into the forking issue (that miners can mine both forks of a chain easily and without consequence, so when forks are started they continue to propagate forever).

Nodes do not propagate double stakes.

[Jabulon]

Uh, I'm not sure what the developers did, but you should probably be aware that without PoW blocks a PeerCoin/NovaCoin fork is vulnerable to the stake burnin vulnerability.

Interesting, I was under the impression that the POS vulnerability was fixed in the next update.

It was -- by using modifiers derived from the entropy of the PoW blocks.  

See in kernel.cpp:

Code:

bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModifier, bool& fGeneratedStakeModifier){
...
}

ComputeNextStakeModifier uses hashes of 64 blocks (both PoW and PoS) as source of entropy.
Compare 64 blocks to forge StakeModifier with 10 blocks to confirm transaction.

FYI, and worth reading. Sunny King response to the matter: https://bitcointalk.org/index.php?topic=144964.0;all

[tacotime]

Read this thread more closely: https://bitcointalk.org/index.php?topic=131901.0

And diff PPCoin 0.2 and 0.3

You'll see why it's a bad idea to turn off PoW

If I understand this correctly, there was additiotal search space caused by insufficient timestamp check and difficulty retarget every block. Both have nothing to do with PoW.

Code:

bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModifier, bool& fGeneratedStakeModifier)
{
    nStakeModifier = 0;
    fGeneratedStakeModifier = false;
    if (!pindexPrev)
    {
        fGeneratedStakeModifier = true;
        return true;  // genesis block's modifier is 0
    }
    // First find current stake modifier and its generation block time
    // if it's not old enough, return the same stake modifier
    int64 nModifierTime = 0;
    if (!GetLastStakeModifier(pindexPrev, nStakeModifier, nModifierTime))
        return error("ComputeNextStakeModifier: unable to get last modifier");
    if (fDebug)
    {
        printf("ComputeNextStakeModifier: prev modifier=0x%016"PRI64x" time=%s\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str());
    }
    if (nModifierTime / nModifierInterval >= pindexPrev->GetBlockTime() / nModifierInterval)
        return true;

    // Sort candidate blocks by timestamp
    vector<pair<int64, uint256> > vSortedByTimestamp;
    vSortedByTimestamp.reserve(64 * nModifierInterval / nTargetSpacing);
    int64 nSelectionInterval = GetStakeModifierSelectionInterval();
    int64 nSelectionIntervalStart = (pindexPrev->GetBlockTime() / nModifierInterval) * nModifierInterval - nSelectionInterval;
    const CBlockIndex* pindex = pindexPrev;
    while (pindex && pindex->GetBlockTime() >= nSelectionIntervalStart)
    {
        vSortedByTimestamp.push_back(make_pair(pindex->GetBlockTime(), pindex->GetBlockHash()));
        pindex = pindex->pprev;
    }
    int nHeightFirstCandidate = pindex ? (pindex->nHeight + 1) : 0;
    reverse(vSortedByTimestamp.begin(), vSortedByTimestamp.end());
    sort(vSortedByTimestamp.begin(), vSortedByTimestamp.end());

    // Select 64 blocks from candidate blocks to generate stake modifier
    uint64 nStakeModifierNew = 0;
    int64 nSelectionIntervalStop = nSelectionIntervalStart;
    map<uint256, const CBlockIndex*> mapSelectedBlocks;
    for (int nRound=0; nRound<min(64, (int)vSortedByTimestamp.size()); nRound++)
    {
        // add an interval section to the current selection round
        nSelectionIntervalStop += GetStakeModifierSelectionIntervalSection(nRound);
        // select a block from the candidates of current round
        if (!SelectBlockFromCandidates(vSortedByTimestamp, mapSelectedBlocks, nSelectionIntervalStop, nStakeModifier, &pindex))
            return error("ComputeNextStakeModifier: unable to select block at round %d", nRound);
        // write the entropy bit of the selected block
        nStakeModifierNew |= (((uint64)pindex->GetStakeEntropyBit()) << nRound);
        // add the selected block from candidates to selected list
        mapSelectedBlocks.insert(make_pair(pindex->GetBlockHash(), pindex));
        if (fDebug && GetBoolArg("-printstakemodifier"))
            printf("ComputeNextStakeModifier: selected round %d stop=%s height=%d bit=%d\n", nRound, DateTimeStrFormat(nSelectionIntervalStop).c_str(), pindex->nHeight, pindex->GetStakeEntropyBit());
    }

    // Print selection map for visualization of the selected blocks
    if (fDebug && GetBoolArg("-printstakemodifier"))
    {
        string strSelectionMap = "";
        // '-' indicates proof-of-work blocks not selected
        strSelectionMap.insert(0, pindexPrev->nHeight - nHeightFirstCandidate + 1, '-');
        pindex = pindexPrev;
        while (pindex && pindex->nHeight >= nHeightFirstCandidate)
        {
            // '=' indicates proof-of-stake blocks not selected
            if (pindex->IsProofOfStake())
                strSelectionMap.replace(pindex->nHeight - nHeightFirstCandidate, 1, "=");
            pindex = pindex->pprev;
        }
        BOOST_FOREACH(const PAIRTYPE(uint256, const CBlockIndex*)& item, mapSelectedBlocks)
        {
            // 'S' indicates selected proof-of-stake blocks
            // 'W' indicates selected proof-of-work blocks
            strSelectionMap.replace(item.second->nHeight - nHeightFirstCandidate, 1, item.second->IsProofOfStake()? "S" : "W");
        }
        printf("ComputeNextStakeModifier: selection height [%d, %d] map %s\n", nHeightFirstCandidate, pindexPrev->nHeight, strSelectionMap.c_str());
    }
    if (fDebug)
    {
        printf("ComputeNextStakeModifier: new modifier=0x%016"PRI64x" time=%s\n", nStakeModifierNew, DateTimeStrFormat(pindexPrev->GetBlockTime()).c_str());
    }

    nStakeModifier = nStakeModifierNew;
    fGeneratedStakeModifier = true;
    return true;
}

Notice how ComputeNextStakeModifier typically includes PoW blocks; you can visualise this if you turn on the debug flags.

What could happen when you don't include PoW blocks and you're only using entropy bits from PoS blocks (GetStakeEntropyBit() from main.cpp)?  Especially if you're producing most of the previous PoS blocks?  Of course, we can be generally assured that entropy bits from PoW miners are completely random because for them not to be would involve them throwing away a lot of work...

I don't think there's any easy fix not including PoW, and if you make the chain completely PoS you run into the forking issue (that miners can mine both forks of a chain easily and without consequence, so when forks are started they continue to propagate forever).

Nodes do not propagate double stakes.

Okay; how do you select which chain is the correct one?

[Jabulon]

Just got an idea on the POS.. does this mean that i am only earning 1% of my total coins every year?

for example a coins worth 1,000 USD will have an interest of 10 USD per year? and the wallet should be left unlock and let it go POS mining?

if that's the case it's a very low profit on holding the coins for a long period of time.. or maybe my understanding is incorrect.
please enlighten me.

The 1% per year means the coin price only needs to rise 1% per year in order for your investment to not lose value. Compare with MINT, the price will have to rise 20% in first year for holders to break even due to higher coin inflation.

1% per annum coin inflation is a big positive feature of BlackCoin. There is no huge new supply of coins to be dumped. If someone wants the coins, they have to buy them at market rate.

Why would the price have to rise for me to break even? Math is hard, but the way I see it, the price of Mint can go down 20% and since I will have 20% more Mint after a year I will still breakeven after a 20% price drop. Why are you are saying the price needs to rise 20% for me to breakeven?

To keep same coin price a 20% inflationary coin has to rise by 20% otherwise the coin price drops. It is due to new coins being added to the supply. A coin with 1% inflation does not have this problem, only on a very tiny scale. If everyone always holds their coins it makes no difference. If everyone dumps their extra coins the price gets diluted downwards.

Colinfx well put. Too many people who mine and trade cryptocoins have a limited understanding of economics and inflation.

The 1% inflation will not suffice to dilute price. It will merely offset the inevitable deflationary process slightly. People will lose coins. People will hoard coins over lengthy periods. People will lose track of wallets, lose passwords, accidentally delete their wallet.dat lol.

[yannis7777]

Wow bc is doing exceptionally well and I am not talking about the price I am talking about rat4, soepkip, xbladex and some other fellas helping the coin get pushed. The rise has not even started yet, yet I am witnessing one of the most vivid and supportive (at the same time) communities in the crypto scene. Congrats guys.

[Hampuz]

Wow bc is doing exceptionally well and I am not talking about the price I am talking about rat4, soepkip, xbladex and some other fellas helping the coin get pushed. The rise has not even started yet, yet I am witnessing one of the most vivid and supportive (at the same time) communities in the crypto scene. Congrats guys.

+1 Fully agreed!

[brightlight]

Someone is massively dumping