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Topic: Cleanup: I'll attack some coins - I owned APEXcoin for 90 blocks - page 4. (Read 17296 times)

legendary
Activity: 826
Merit: 1002
amarha
So, found any holes the Nxt devs missed in their implementation?  Smiley

I think so... but as I said, I need some time to implement the attack and completely understand the implications... attacking still requires a lot of stake, looking how to improve that...

Which is why borrowing state becomes an option for someone wishing to attack a POS coin. That is the essence of the "Second Pirate Savings and Trust" attack.

I think borrowing coins/leased forging and such is the only major danger that I've seen thus far to a solid PoS set up like NXT. In general I think PoS communities need to be vigilant about discouraging mass lending as it seems to be the only plausible way that an attacker could gain a sufficient amount of stake.
sr. member
Activity: 490
Merit: 250
I don't really come from outer space.
Which is why borrowing state becomes an option for someone wishing to attack a POS coin.

So where can one lend large amounts of PoS coins?

Nxt allows balance leasing.  The coins stay with the original account, but the PoS power goes to whom the balanced is leased to.   One Nxt is a simulated Bitcoin mining rig so think of it as a simulation of a Bitcoin pool.
legendary
Activity: 996
Merit: 1013
Which is why borrowing state becomes an option for someone wishing to attack a POS coin.

So where can one lend large amounts of PoS coins?
legendary
Activity: 3836
Merit: 4969
Doomed to see the future and unable to prevent it
This looks interesting, reminds me of BCX and Monero




Not even close, BCX was full of shit.
legendary
Activity: 2282
Merit: 1050
Monero Core Team
So, found any holes the Nxt devs missed in their implementation?  Smiley

I think so... but as I said, I need some time to implement the attack and completely understand the implications... attacking still requires a lot of stake, looking how to improve that...

Which is why borrowing state becomes an option for someone wishing to attack a POS coin. That is the essence of the "Second Pirate Savings and Trust" attack.
legendary
Activity: 924
Merit: 1000
This looks interesting, reminds me of BCX and Monero

what happened with that? was there an attack or not?

There was an attempted attack, but it fizzled.
member
Activity: 106
Merit: 10
yes, sometimes I'm a cynical SOB
This looks interesting, reminds me of BCX and Monero

what happened with that? was there an attack or not?
member
Activity: 68
Merit: 10
these poor coins are in trouble  Grin
hero member
Activity: 508
Merit: 500
Jahaha
This looks interesting, reminds me of BCX and Monero
legendary
Activity: 3836
Merit: 4969
Doomed to see the future and unable to prevent it
Keep going, This is what keeps me interested while all my coins plummet. Cheesy
member
Activity: 106
Merit: 10
yes, sometimes I'm a cynical SOB
So, found any holes the Nxt devs missed in their implementation?  Smiley

I think so... but as I said, I need some time to implement the attack and completely understand the implications... attacking still requires a lot of stake, looking how to improve that...

Were you not able to gather enough testnet stake to test your theories?

I didn't even get to the part were I know how much I need. Patience! remember it took me some time with Apex but I delivered.
legendary
Activity: 826
Merit: 1002
amarha
So, found any holes the Nxt devs missed in their implementation?  Smiley

I think so... but as I said, I need some time to implement the attack and completely understand the implications... attacking still requires a lot of stake, looking how to improve that...

Were you not able to gather enough testnet stake to test your theories?
member
Activity: 106
Merit: 10
yes, sometimes I'm a cynical SOB
So, found any holes the Nxt devs missed in their implementation?  Smiley

I think so... but as I said, I need some time to implement the attack and completely understand the implications... attacking still requires a lot of stake, looking how to improve that...
hero member
Activity: 574
Merit: 500
Bolded

Some simple questions about nxt so I don't have to look them up:

1) Is transparent forging really implemented? I thought not

The part that allows you to predict the next block is, you should be able to confirm this yourself using the tool above. TF is several interlocking bits so you can't really pick a point and say "that's when TF began". And not all of it is implemented yet.

2) Is https://bitbucket.org/JeanLucPicard/nxt the latest source code? if not, where do I find it? do I really have to decompile Java?

I believe so. Every version ships with the source code in the 'src' folder so you could use that for the latest version. Not sure it is in as usable format though


3) If account A transfers some amount to account B (which was already verified) at block N, can B use that stake to forge block N+1? if not, when will it become part of B's effective balance?

You have to wait for N+1440 blocks before it counts in B's effective balance again. You can't broadcast a transaction, move the Nxt, broadcast again in the next block in a new account, move, broadcast move etc. using the same NXT.


4) Is re-leasing possible? if A leases to B, can B re-lease to C without approval from A?

No

5) which is the best place to ask these questions? nxtforums? which section?

Nxtforum is best.

Technical general questions: https://nxtforum.org/general/
Transparent Forging: https://nxtforum.org/transparent-forging/


Thanks!

You're welcome. Keep it up!




So, found any holes the Nxt devs missed in their implementation?  Smiley
hero member
Activity: 614
Merit: 506
Applications
He is using testnet as well. In fact he's just been working on NXT testnet at the request of many. I'm guessing you haven't read the thread thus far. He's doing a good job so far and lots of people are interested in seeing more of his attempts.

This type of thing is critical for PoS to really be considered a robust consensus system. Actually it's not great that it's taken this long for some good public stress testing/attacks. Anyone interested in the idea of PoS should be supporting people who can help strengthen it.

I'm not saying that I fully agree with how this "stress testing" is being done, but am glad to actually see it done sooner than later. Just imagine if this wasn't pointed out, flaws of P.O.S. in 100's of coins till there was Millions of people holding 100's of wallets not opened for months? Not many people can sit back & think about how many things in the world are "stress tested", creating something more reliable & stable. Just think about a world without "stress testing", the wheel would still be just a wheel & break from the slightest bump Wink

// Not that wording would change much, but maybe replace "attack < stress testing for the public".
legendary
Activity: 1092
Merit: 1000
Kind of like we have to give the prize to the 2nd or 3rd place runner, cause the 1st one was too fast.
It would affect staking for a lot of users, but would be worth it, if it could remove the 51% vulnerability for all POS coins.
but you didn't solve anything... how do you know the 2nd or 3rd place runners are not the attacker? maybe he placed the first one to trick you into selecting the second one which is also his...
Thanks for responding, it would not know if the 2nd or 3rd place or 15th are attacks or normal,
it would only block everything that could be a potential attack , which means some normal stakers would also have their stakes blocked , if it had the potential and was over the % line and only allow stakers below the % to ever add any stakes.  Basically can not a filter using some calculations involving total # of coins and current difficulty be created to block potential attacks , even though it will also block some normal stakers.
That is what I was wondering.

Thanks,
Kiklo

 
member
Activity: 106
Merit: 10
yes, sometimes I'm a cynical SOB
Kind of like we have to give the prize to the 2nd or 3rd place runner, cause the 1st one was too fast.
It would affect staking for a lot of users, but would be worth it, if it could remove the 51% vulnerability for all POS coins.
but you didn't solve anything... how do you know the 2nd or 3rd place runners are not the attacker? maybe he placed the first one to trick you into selecting the second one which is also his...

The chance of forging a block does not depend on how long it is since the previous block you forged. It depends on what fraction of the forging coins you have.
It depends on both. Your "hit" is calculated by multiplying your stake by the seconds since the last block.

What is your criteria for a successful attack?
this one is easy: either successful double spend or proving you have 10 (or whatever is required for confirmation) blocks in a row.
I did both for Apex.
legendary
Activity: 1092
Merit: 1000
But killing zombies is a lot of fun.

so is this Smiley

c'mon, APEX's price hasn't moved, and they didn't even have checkpointing servers (not that it would have helped, but It shows they didn't care or they were not prepared to run a coin).
I like to think I'm not destroying work, I'm building a more secure future. For our kids! would anybody think about the children !?

Hey cynicSOB,
what do you think about that: https://bitcointalksearch.org/topic/m.10208018

Would it lower your success?

Cheers,
Ray


I think it wouldn't work: how can you tell an attack from normal use? if you have 2 chains that look similar but have one conflicting tx you have to choose one, there's just no way to avoid that. How do you define which is the "good" one? an attack may not even change the difficulty

The theory behind it is , it blocks both Normal Use or Attack of anything that might have the potential to stake over the % where the attack could happen. So in theory if there are 2 blocks, anything over the % line is blocked, but anything below the % line is accepted normally, and if you have 2 block come in 1 over the % line , and 1 under , the one under it would be accepted , complete opposite of its normal behavior.
If both blocks are under the % line, then it stakes normally. If both are over the % line , then both are blocked for another block under the % line.
Kind of like we have to give the prize to the 2nd or 3rd place runner, cause the 1st one was too fast.
It would affect staking for a lot of users, but would be worth it, if it could remove the 51% vulnerability for all POS coins.

Thanks,
Kiklo
newbie
Activity: 34
Merit: 0
I like how the NXT community is pushing for an attack on its blockchain!

The Nxt community knows the Nxt blockchain doesn't have much to do with APEX.
Let's have it... Wink
legendary
Activity: 1680
Merit: 1001
CEO Bitpanda.com
I like how the NXT community is pushing for an attack on its blockchain!
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