Security analysis of PoW/PoS hybrids with low PoW reward

[goblynn]

The Blackcoin DEV dont wanna answer..

He throws the rock and hides the hand.

maybe hes AFK?

He started the Thread minutes ago!!!!!!!

check time stamp again..it was a 5 hours ago

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[stormia]

Or he is sleeping.

This is not an attack on either Mint or Shacoin, this is purely an observation on hybrid pow/pos systems. If you want to discuss PoS security i do invite you to join IRC ##blackcoin on freenode and seek out rat4 there when he is awake.

Also, i'm not the dev of blackcoin

Yeah, as a professional he has more important business than engaging in this peeing contest. Make what you will of his analysis, do your own due diligence and try to come to rational conclusions based on what you learn rather than your emotional ties to this or that coin.

You are to be called out for the blatant and utter hypocrisy of Fudding the Blackcoin thread for days with inflammatory dirt, and then having hissy-fits when the Blackcoin dev weighs in with a technical statement, and you crying "fud, fud!"

Shame on you all for your childishness and abysmal conduct, which only hinders the progress of cryptocurrency. Examine your motivations more thoroughly.

He has more important business to do? Yet he starts this thread? And then walks away? It was important enough for him to start the thread but not important enough for him to reply to responses? Still, nobody has addressed what I brought up and nobody has addressed the "time bomb" that greentea brought up. Now you are just trying to defame us on a personal level instead of addressing the content of what we said.

Examine the motivations of your dev more thoroughly.

[stormia]

Or he is sleeping.

This is not an attack on either Mint or Shacoin, this is purely an observation on hybrid pow/pos systems. If you want to discuss PoS security i do invite you to join IRC ##blackcoin on freenode and seek out rat4 there when he is awake.

Also, i'm not the dev of blackcoin

Yeah, as a professional he has more important business than engaging in this peeing contest. Make what you will of his analysis, do your own due diligence and try to come to rational conclusions based on what you learn rather than your emotional ties to this or that coin.

You are to be called out for the blatant and utter hypocrisy of Fudding the Blackcoin thread for days with inflammatory dirt, and then having hissy-fits when the Blackcoin dev weighs in with a technical statement, and you crying "fud, fud!"

Shame on you all for your childishness and abysmal conduct, which only hinders the progress of cryptocurrency. Examine your motivations more thoroughly.

He has more important business to do? Yet he starts this thread? And then walks away? It was important enough for him to start the thread but not important enough for him to reply to responses? Still, nobody has addressed what I brought up and nobody has addressed the "time bomb" that greentea brought up. Now you are just trying to defame us on a personal level instead of addressing the content of what we said.

Examine the motivations of your dev more thoroughly.

May I suggest we leave this discussion to technical users, and give them their time? No need to be impatient, the answers will be in this thread. Sorry for this spam comment.

Agreed. I will wait patiently for a technical response to what I said about the relative security of PoS/PoW vs pure PoS, and to the "timebomb".

[stormia]

Or he is sleeping.

This is not an attack on either Mint or Shacoin, this is purely an observation on hybrid pow/pos systems. If you want to discuss PoS security i do invite you to join IRC ##blackcoin on freenode and seek out rat4 there when he is awake.

Also, i'm not the dev of blackcoin

Yeah, as a professional he has more important business than engaging in this peeing contest. Make what you will of his analysis, do your own due diligence and try to come to rational conclusions based on what you learn rather than your emotional ties to this or that coin.

You are to be called out for the blatant and utter hypocrisy of Fudding the Blackcoin thread for days with inflammatory dirt, and then having hissy-fits when the Blackcoin dev weighs in with a technical statement, and you crying "fud, fud!"

Shame on you all for your childishness and abysmal conduct, which only hinders the progress of cryptocurrency. Examine your motivations more thoroughly.

He has more important business to do? Yet he starts this thread? And then walks away? It was important enough for him to start the thread but not important enough for him to reply to responses? Still, nobody has addressed what I brought up and nobody has addressed the "time bomb" that greentea brought up. Now you are just trying to defame us on a personal level instead of addressing the content of what we said.

Examine the motivations of your dev more thoroughly.

May I suggest we leave this discussion to technical users, and give them their time? No need to be impatient, the answers will be in this thread. Sorry for this spam comment. I'll delete my earlier posts. I had nothing to add anyways. I suggest we do the same so the thread is clean and can be constructive

I won't delete my initial post as it contains content which I want addressed, but I do regret having been so offensive in the manner of its presentation. Nonetheless, it is the content that matters.

[Jabulon]

Or he is sleeping.

This is not an attack on either Mint or Shacoin, this is purely an observation on hybrid pow/pos systems. If you want to discuss PoS security i do invite you to join IRC ##blackcoin on freenode and seek out rat4 there when he is awake.

Also, i'm not the dev of blackcoin

Yeah, as a professional he has more important business than engaging in this peeing contest. Make what you will of his analysis, do your own due diligence and try to come to rational conclusions based on what you learn rather than your emotional ties to this or that coin.

You are to be called out for the blatant and utter hypocrisy of Fudding the Blackcoin thread for days with inflammatory dirt, and then having hissy-fits when the Blackcoin dev weighs in with a technical statement, and you crying "fud, fud!"

Shame on you all for your childishness and abysmal conduct, which only hinders the progress of cryptocurrency. Examine your motivations more thoroughly.

He has more important business to do? Yet he starts this thread? And then walks away? It was important enough for him to start the thread but not important enough for him to reply to responses? Still, nobody has addressed what I brought up and nobody has addressed the "time bomb" that greentea brought up. Now you are just trying to defame us on a personal level instead of addressing the content of what we said.

Examine the motivations of your dev more thoroughly.

May I suggest we leave this discussion to technical users, and give them their time? No need to be impatient, the answers will be in this thread. Sorry for this spam comment. I'll delete my earlier posts. I had nothing to add anyways. I suggest we do the same so the thread is clean and can be constructive

I won't delete my initial post as it contains content which I want addressed, but I do regret having been so offensive in the manner of its presentation. Nonetheless, it is the content that matters.

All parties agreed then, myself included, if the discussion can be maintained as a discussion and not a repeat of yesterday.

[artiface]

This is a joke. Nice try to spread FUD about other coins, rat4, to try and promote your pure PoS blackcoin. How is it that Blackcoin prevents attack forks as a pure PoS coin, again?

You say "a sequential chain of PoW blocks can be mined in a flash."
Which is not true. Sure, you could mine all of the PoW blocks that occur sequentially, but there will be many, many more PoS blocks that interrupt those far and few apart PoW blocks. In a PoS/PoW hybrid there is no way to predict or control whether or not the next block will be PoS or PoW and therefore you cannot guarantee you will be in control of a long stream of blocks unless you have 51% of the PoW and PoS power.

Now, this brings up an issue with pure PoS coins such as your Blackcoin... That I have yet to be seen answered in any technical detail. How, when it is pure PoS and it IS known that every block in a row will be PoS, can you prevent an attack such as the one anonymousg64 brings up:

im still on the fence


can someone explain how this stops someone from generating lots of PoS blocks 20 days in the future from a bunch of TX's with small interval, whether through one or multiple wallets

Code:

ss << nStakeModifier;
ss << nTimeBlockFrom << nTxPrevOffset << txPrev.nTime << prevout.n << nTimeTx;
hashProofOfStake = Hash(ss.begin(), ss.end());
if(CBigNum(hashProofOfStake) > bnCoinDayWeight * bnTargetPerCoinDay)
    return false;

im not well enough versed with the code to know what these variable names imply

Without PoW blocks to interrupt such an attack, how is it prevented?

This thread of yours is in really bad taste, rat4, you should find better ways of promoting your coin.

I await your reply, and your explanation as to how PoS coins are safe from a TX/coinage attack.

This was answered many times in the black coin thread and here you are asking it again.  

https://bitcointalk.org/index.php?topic=469640.msg5971244#msg5971244

Oh look at YOUR REPLY
https://bitcointalk.org/index.php?topic=469640.msg5971375#msg5971375

Thank you both, my fears have been quelled and I've learned some new stuff:)

So why are you here bringing it up again today in a new thread?

[stormia]

This is a joke. Nice try to spread FUD about other coins, rat4, to try and promote your pure PoS blackcoin. How is it that Blackcoin prevents attack forks as a pure PoS coin, again?

You say "a sequential chain of PoW blocks can be mined in a flash."
Which is not true. Sure, you could mine all of the PoW blocks that occur sequentially, but there will be many, many more PoS blocks that interrupt those far and few apart PoW blocks. In a PoS/PoW hybrid there is no way to predict or control whether or not the next block will be PoS or PoW and therefore you cannot guarantee you will be in control of a long stream of blocks unless you have 51% of the PoW and PoS power.

Now, this brings up an issue with pure PoS coins such as your Blackcoin... That I have yet to be seen answered in any technical detail. How, when it is pure PoS and it IS known that every block in a row will be PoS, can you prevent an attack such as the one anonymousg64 brings up:

im still on the fence


can someone explain how this stops someone from generating lots of PoS blocks 20 days in the future from a bunch of TX's with small interval, whether through one or multiple wallets

Code:

ss << nStakeModifier;
ss << nTimeBlockFrom << nTxPrevOffset << txPrev.nTime << prevout.n << nTimeTx;
hashProofOfStake = Hash(ss.begin(), ss.end());
if(CBigNum(hashProofOfStake) > bnCoinDayWeight * bnTargetPerCoinDay)
    return false;

im not well enough versed with the code to know what these variable names imply

Without PoW blocks to interrupt such an attack, how is it prevented?

This thread of yours is in really bad taste, rat4, you should find better ways of promoting your coin.

I await your reply, and your explanation as to how PoS coins are safe from a TX/coinage attack.

This was answered many times in the black coin thread and here you are asking it again.  

https://bitcointalk.org/index.php?topic=469640.msg5971244#msg5971244

Oh look at YOUR REPLY
https://bitcointalk.org/index.php?topic=469640.msg5971375#msg5971375

Thank you both, my fears have been quelled and I've learned some new stuff:)

So why are you here bringing it up again today in a new thread?

Because the answers that you speak of are just links to a comment from Sunny King, which actually only applies to PoS/PoW hybrids- as that is what he was working with. Am I mistaken? I still await a technical response that pertains to pure PoS specifically.

If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.

I will patiently await a technical response which pertains specifically to pure PoS and a technical response to my initial comment which also outlines why I think PoS/PoW hybrid systems are not vulnerable in the manner that rat4 proposes.

[artiface]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

[stormia]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right? Was it designed for pure PoS? Wasn't it designed by Sunny King for a PoS/PoW hybrid (peercoin)?

The second point you reiterated seems legit to me.

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

[artiface]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right?

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

I'm not giving you heat, i'm only answering your question.. again.

Saying Sunny King's fix only applies to POS/POW hybrids is incorrect, it fixed the POS protocol. Period. 

The timebomb attack is not feasible because coins do not stake on age alone, there are other factors.   Even if you could guarantee that all your coins ages were spaced at a minimum interval there is no guarantee they will all stake at their intervals. Also POS blocks have a target time interval, so coins that were eligible to stake too soon would not generate blocks any faster than the target interval, there is no way that one person could force their coins to be the ones to generate stake for many consecutive intervals.  This attack is pure nonsense.  

[stormia]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right?

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

I'm not giving you heat, i'm only answering your question.. again.

Saying Sunny King's fix only applies to POS/POW hybrids is incorrect, it fixed the POS protocol. Period.  

The timebomb attack is not feasible because coins do not stake on age alone, there are other factors.   Even if you could guarantee that all your coins ages were spaced at a minimum interval there is no guarantee they will all stake at their intervals. Also POS blocks have a target time interval, so coins that were eligible to stake too soon would not generate blocks any faster than the target interval, there is no way that one person could force their coins to be the ones to generate stake for many consecutive intervals.  This attack is pure nonsense.  

But Sunny King fixed PoS in the context of PoS/PoW hybrid, not pure PoS. Right?

[artiface]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right?

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

I'm not giving you heat, i'm only answering your question.. again.

Saying Sunny King's fix only applies to POS/POW hybrids is incorrect, it fixed the POS protocol. Period.  

The timebomb attack is not feasible because coins do not stake on age alone, there are other factors.   Even if you could guarantee that all your coins ages were spaced at a minimum interval there is no guarantee they will all stake at their intervals. Also POS blocks have a target time interval, so coins that were eligible to stake too soon would not generate blocks any faster than the target interval, there is no way that one person could force their coins to be the ones to generate stake for many consecutive intervals.  This attack is pure nonsense.  

But Sunny King fixed PoS in the context of PoS/PoW hybrid, not pure PoS. Right?

Since there have not been any other pure POS coins yes the fix was originally applied to a POS/POW hybrid.  Nevertheless the fix is for the POS protocol and did nothing to POW. The fix ensured that POS was a secure way to generate blocks to secure a blockchain.  If you know of any vulnerabilities in POS please make them known so they can be addressed.

[stormia]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right?

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

I'm not giving you heat, i'm only answering your question.. again.

Saying Sunny King's fix only applies to POS/POW hybrids is incorrect, it fixed the POS protocol. Period.  

The timebomb attack is not feasible because coins do not stake on age alone, there are other factors.   Even if you could guarantee that all your coins ages were spaced at a minimum interval there is no guarantee they will all stake at their intervals. Also POS blocks have a target time interval, so coins that were eligible to stake too soon would not generate blocks any faster than the target interval, there is no way that one person could force their coins to be the ones to generate stake for many consecutive intervals.  This attack is pure nonsense.  

But Sunny King fixed PoS in the context of PoS/PoW hybrid, not pure PoS. Right?

Since there have not been any other pure POS coins yes the fix was originally applied to a POS/POW hybrid.  Nevertheless the fix is for the POS protocol and did nothing to POW. The fix ensured that POS was a secure way to generate blocks to secure a blockchain.  If you know of any vulnerabilities in POS please make them known so they can be addressed.

I don't know the specific vulnerabilities, I'm not saying that there necessarily are any. My argument is purely from a logic standpoint. If the security of PoS was in any way dependent upon PoW in the PoS/PoW hybrid system, then just because the PoS security flaws were fixed in that context doesn't mean they will be fixed when PoS is standing alone, or that new security flaws wouldn't be introduced when PoS stands alone. So the question is, did Sunny build/fix PoS to be completely secure standing alone or was it in anyway dependent on PoW? I guess this is ultimately what I am trying to figure out.

[artiface]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right?

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

I'm not giving you heat, i'm only answering your question.. again.

Saying Sunny King's fix only applies to POS/POW hybrids is incorrect, it fixed the POS protocol. Period.  

The timebomb attack is not feasible because coins do not stake on age alone, there are other factors.   Even if you could guarantee that all your coins ages were spaced at a minimum interval there is no guarantee they will all stake at their intervals. Also POS blocks have a target time interval, so coins that were eligible to stake too soon would not generate blocks any faster than the target interval, there is no way that one person could force their coins to be the ones to generate stake for many consecutive intervals.  This attack is pure nonsense.  

But Sunny King fixed PoS in the context of PoS/PoW hybrid, not pure PoS. Right?

Since there have not been any other pure POS coins yes the fix was originally applied to a POS/POW hybrid.  Nevertheless the fix is for the POS protocol and did nothing to POW. The fix ensured that POS was a secure way to generate blocks to secure a blockchain.  If you know of any vulnerabilities in POS please make them known so they can be addressed.

I don't know the specific vulnerabilities, I'm not saying that there necessarily are any. My argument is purely from a logic standpoint. If the security of PoS was in any way dependent upon PoW in the PoS/PoW hybrid system, then just because the PoS security flaws were fixed in that context doesn't mean they will be fixed when PoS is standing alone, or that new security flaws wouldn't be introduced when PoS stands alone. So the question is, did Sunny build/fix PoS to be completely secure standing alone or was it in anyway dependent on PoW? I guess this is ultimately what I am trying to figure out.

POS and POW are completely separate and different systems.  They do not depend on each other at all.  They work separately and can compliment each other as 2 different methods to secure a block chain or they can each stand alone. 

[Zzzack]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right?

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

I'm not giving you heat, i'm only answering your question.. again.

Saying Sunny King's fix only applies to POS/POW hybrids is incorrect, it fixed the POS protocol. Period.  

The timebomb attack is not feasible because coins do not stake on age alone, there are other factors.   Even if you could guarantee that all your coins ages were spaced at a minimum interval there is no guarantee they will all stake at their intervals. Also POS blocks have a target time interval, so coins that were eligible to stake too soon would not generate blocks any faster than the target interval, there is no way that one person could force their coins to be the ones to generate stake for many consecutive intervals.  This attack is pure nonsense.  

But Sunny King fixed PoS in the context of PoS/PoW hybrid, not pure PoS. Right?

Since there have not been any other pure POS coins yes the fix was originally applied to a POS/POW hybrid.  Nevertheless the fix is for the POS protocol and did nothing to POW. The fix ensured that POS was a secure way to generate blocks to secure a blockchain.  If you know of any vulnerabilities in POS please make them known so they can be addressed.

I don't know the specific vulnerabilities, I'm not saying that there necessarily are any. My argument is purely from a logic standpoint. If the security of PoS was in any way dependent upon PoW in the PoS/PoW hybrid system, then just because the PoS security flaws were fixed in that context doesn't mean they will be fixed when PoS is standing alone, or that new security flaws wouldn't be introduced when PoS stands alone. So the question is, did Sunny build/fix PoS to be completely secure standing alone or was it in anyway dependent on PoW? I guess this is ultimately what I am trying to figure out.

Sunny built them to be dependent on each other. POW is a proven system. POW/POS is a proven system. POS is not and may be vulnerable to attack.

OP's point is that a POW/POS system with very small rewards creates a weak POW system that someone could exploit and it would essentially be the same as a standalone POS system which may be vulnerable.

[artiface]

That is YOUR reply I quoted.

You must have read the answer at one point, because YOU commented that your question was answered, but I will summarize it again here just to be perfectly clear.

• Blackcoin use POS 0.3.0 protocol which has no known vulnerabilities at this time
• The "attack" suggested is impossible because coins do not stake on age alone, therefore making deposits at small intervals in no way guarantees you will generate POS blocks at those intervals.  In fact splitting coins to generate these intervals will make the chance of staking at each interval even less

Right, it uses "POS 0.3.0 protocol which has no known vulnerabilities at this time" in the context of a PoS/PoW hybrid, right? It has never been tested in the context of pure PoS, right?

I will restate: If i said said anything further about it on the blackcoin thread, I would have been ran out of there and labeled as a FUDer.
Similar to how what I am saying now, not on the blackcoin thread, is drawing so much heat.

I'm not giving you heat, i'm only answering your question.. again.

Saying Sunny King's fix only applies to POS/POW hybrids is incorrect, it fixed the POS protocol. Period.  

The timebomb attack is not feasible because coins do not stake on age alone, there are other factors.   Even if you could guarantee that all your coins ages were spaced at a minimum interval there is no guarantee they will all stake at their intervals. Also POS blocks have a target time interval, so coins that were eligible to stake too soon would not generate blocks any faster than the target interval, there is no way that one person could force their coins to be the ones to generate stake for many consecutive intervals.  This attack is pure nonsense.  

But Sunny King fixed PoS in the context of PoS/PoW hybrid, not pure PoS. Right?

Since there have not been any other pure POS coins yes the fix was originally applied to a POS/POW hybrid.  Nevertheless the fix is for the POS protocol and did nothing to POW. The fix ensured that POS was a secure way to generate blocks to secure a blockchain.  If you know of any vulnerabilities in POS please make them known so they can be addressed.

I don't know the specific vulnerabilities, I'm not saying that there necessarily are any. My argument is purely from a logic standpoint. If the security of PoS was in any way dependent upon PoW in the PoS/PoW hybrid system, then just because the PoS security flaws were fixed in that context doesn't mean they will be fixed when PoS is standing alone, or that new security flaws wouldn't be introduced when PoS stands alone. So the question is, did Sunny build/fix PoS to be completely secure standing alone or was it in anyway dependent on PoW? I guess this is ultimately what I am trying to figure out.

Sunny built them to be dependent on each other. POW is a proven system. POW/POS is a proven system. POS is not and may be vulnerable to attack.

OP's point is that a POW/POS system with very small rewards creates a weak POW system that someone could exploit and it would essentially be the same as a standalone POS system which may be vulnerable.

You clearly did not understand the OP. That is not the OP's point at all.  The OP's point is that POW/POS hybrid is vulnerable to a double spend attack by a POS block negating/orphaing a POW chain with enough blocks to have confirmed transactions.

I expect you have never looked at the source code of a POW/POW hybrid, because it it very clear POS and POW are not dependent on each other in any way.  They are completely separate methods.  It is true that POS only has never been tried before, but the POS system is secure in itself and has no known vulnerabilities.   POW is a proven system with a known vulnerability called 51% attack which is why POS was added.  POS/POW may be vulnerable by the method explained in the OP.   POS alone, again has no known vulnerabilities besides a 51% attack which would require owning 51% of the coins which would mean you already basically control the money supply and would devalue your own coins.

[presstab]

Isn't it true that most PoW/PoS hybrids have the same target block generation speed for both systems?  So why would there be many PoW blocks in a row unless it happens by random chance?

[TrollboxChamp]

Some of yall are crazy.

He just had to hard fork his coin. Do you think he did this to blow smoke out his ass? hahaha

[artiface]

Isn't it true that most PoW/PoS hybrids have the same target block generation speed for both systems?  So why would there be many PoW blocks in a row unless it happens by random chance?

If the difficulty is very low due to low network hash rate then applying a substantially higher hashrate can cause many POW blocks to be generated quickly, much quicker than the target rate.

[gonzoucab]

Today theres nothing more secure and proven that POS/POW Hybrid

To attack you need 1/2 os POS and 1/2 POW

Add cost to the attact.