Escrow attack on Proof-of-Stake - page 2.

Sunny King

legendary

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Quote from: Balthazar on April 18, 2013, 02:11:10 PM

Quote from: xorxor on April 18, 2013, 02:06:00 PM

if you find a block and destroy coinage of 10000 coins lying in there for 365 days, wou will be rewarded 100 coins.

No, because there is limit for coinage in PPC and NVC, 90 days. You will receive ~ 25 coins.

xorxor is correct, 90 day limit only applies to kernel hash weighting, but when calculating reward full coin age is used. So you do get 100 coins provided you are online long enough to generate stakes.

Balthazar

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Quote from: xorxor on April 18, 2013, 02:06:00 PM

if you find a block and destroy coinage of 10000 coins lying in there for 365 days, wou will be rewarded 100 coins.

~~No, because there is limit for coinage in PPC and NVC, 90 days. You will receive ~ 25 coins.~~

Quote from: tacotime on April 18, 2013, 02:08:32 PM

The new protocol (as far as I can tell) just makes it harder to spam consecutive blocks from a single source (again, it's hard to tell because SK doesn't want to explain it in simple pseudocode) -- but I think you can still do it if you keep multiple wallets. For instance, if you have 500 clients all with some coins 90 days old, and you keep them offline then suddenly bring them online, you might be able too.

There is no difference between "1 wallet" and "500 wallets" configurations.

tacotime

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Quote from: xorxor on April 18, 2013, 02:06:00 PM

stake is only generated up to 90 days so it cannot be super charged for an attack, also new 3.0 protocol has protection against finding pos block one by one.

checkpointing is still there, but just in case of som unknown vulnerabilities. users trust developer so there is actualy not mush pressure from PPC supporters to remove it.

there are no known possible atacks that would be easier on PPC than on any other coin including BTC.

The new protocol (as far as I can tell) just makes it harder to spam consecutive blocks from a single source (again, it's hard to tell because SK doesn't want to explain it in simple pseudocode) -- but I think you can still do it if you keep multiple wallets. For instance, if you have 500 clients all with some coins 90 days old, and you keep them offline then suddenly bring them online, you might be able too.

xorxor

sr. member

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coindays is not stake!!!

coindays destroyed in POS block generation are awarded in a 1% roi.
if you find a block and destroy coinage of 10000 coins lying in there for 365 days, wou will be rewarded 100 coins.

but that would not make it easy for you to attack. generation is baset not on coinage, but on stake.
stake is only generated up to 90 days so it cannot be super charged for an attack, also new 3.0 protocol has protection against finding pos block one by one.

checkpointing is still there, but just in case of som unknown vulnerabilities. users trust developer so there is actualy not mush pressure from PPC supporters to remove it.

there are no known possible atacks that would be easier on PPC than on any other coin including BTC.

tacotime

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Merit: 1005

This is prevented by checkpointing (centralized control)

https://bitcointalksearch.org/topic/m.1636798

If you can circumvent checkpointing, you can easily double spend with stake blocks

Exchanges can defend against these attacks by simply ignorning stake blocks for the purpose of confirmation.

astor

newbie

Activity: 39

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Yes I've read the paper.

Maybe you didn't understand the attack. The attack is that the escrow service cooperates with a miner to destroy coin days.

magnificat_mafia

newbie

Activity: 36

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have you read the white paper. stop being such a scrub

astor

newbie

Activity: 39

Merit: 0

In a Proof-of-Stake system similar to bitcoin, a large number of coins could lie dormant and accrue 'coin days'. If these coins are in escrow, like on Mt.Gox, their 'coin days' could be used to do an attack on the network.

Thus any large escrow service would be a threat to the network, in addition to large miners.

Thus either escrow services must pay interest, or the need for escrow should be eliminated by a better block chain design and p2p exchanges.

Topic: Escrow attack on Proof-of-Stake - page 2. (Read 1705 times)