Nxt source code flaw reports - page 8.

opticalcarrier

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Quote from: FrictionlessCoin on January 31, 2014, 01:07:13 PM

Quote from: jettico on January 31, 2014, 12:55:19 PM

Good algorithm works equally good on 2 wallets, 3 wallets and 101 wallets and indefinite number of wallets. Bad algorithm needs someone like Come-from-Beyond to make unverifiable claims that 'it works, believe me!'

C'mon! It's not religion, it's programming!

The right way to do this is to have some penalty for fat wallets and encourage a lot of small wallets. So 100 small wallets should make more than 1 fat wallet.

ok so then i break down my one 50M account into fiftty 1M accounts

come on you're going to have to do better than this. if you fell for this logical trap, I dont see how you are EVER going to do your own coin...

jettico

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I'm tried of your blindfoldness as well.

Ah, maybe some other NXT developer knows elementary statistics well enough to understand this?

Come-from-Beyond

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Quote from: jettico on January 31, 2014, 12:55:19 PM

Good algorithm works equally good on 2 wallets, 3 wallets and 101 wallets and indefinite number of wallets. Bad algorithm needs someone like Come-from-Beyond to make unverifiable claims that 'it works, believe me!'

C'mon! It's not religion, it's programming!

I'm tired of ur trolling. U r in my ignore list for 3 days.

FrictionlessCoin

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Cryptotalk.org - Get paid for every post!

Quote from: jettico on January 31, 2014, 12:55:19 PM

Good algorithm works equally good on 2 wallets, 3 wallets and 101 wallets and indefinite number of wallets. Bad algorithm needs someone like Come-from-Beyond to make unverifiable claims that 'it works, believe me!'

C'mon! It's not religion, it's programming!

The right way to do this is to have some penalty for fat wallets and encourage a lot of small wallets. So 100 small wallets should make more than 1 fat wallet.

jettico

member

Activity: 80

Merit: 10

Good algorithm works equally good on 2 wallets, 3 wallets and 101 wallets and indefinite number of wallets. Bad algorithm needs someone like Come-from-Beyond to make unverifiable claims that 'it works, believe me!'

C'mon! It's not religion, it's programming!

Come-from-Beyond

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Quote from: jettico on January 31, 2014, 12:39:22 PM

Yep. And this prediction is non-democratic.

U r wrong. Read more about TF or ask questions.

Come-from-Beyond

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Quote from: jettico on January 31, 2014, 12:37:30 PM

1) Wow! You admitted it! Now tell me how you're going to fix this.

It was always known. It doesn't need to be fixed.

Quote from: jettico on January 31, 2014, 12:37:30 PM

2) It is not small. In fact it is rather huge. Consider one 100K and 100x 1K accounts:

Stopped reading here. Come back with numbers that accord the reality. Add unknown number of accounts with total balance == 1'000'000'000 - 100'000 - 100*1'000 == 999'800'000.

Come-from-Beyond

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Quote from: salsacz on January 31, 2014, 12:37:02 PM

I FOUND IT!

A fatal flaw is called "FrictionlessCoin"!

No, this was planned but it's not the injected flaw.

Come-from-Beyond

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Quote from: jettico on January 31, 2014, 12:29:00 PM

Quote from: Come-from-Beyond on January 30, 2014, 06:34:53 PM

<...>
"4747" forged 13.8% of all blocks. Theoretically "4747" should have forged (50M / 1000M) * (500% / 100%) = 5% * 5 = 25% of all blocks if he forged all the time and without orphaned blocks.

"if he forged all the time "

Is it known how much time he used?
What if he used only half of the time ...
Wouldn't the expected % then be 12.5% < 13.8% ?

More statistics, plz

Those I've wanted from the beginning ...

All the stats r in the blockchain. Some data is not available, for example, rate of orphaned blocks.
[/quote]

First red phrase contradicts second red phrase because of the green phrase.
[/quote]

Well, looks like u r starting to troll. Cool down and come back with something more valuable than ur personal opinion.

jettico

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Quote from: Come-from-Beyond on January 31, 2014, 12:24:29 PM

Quote from: jettico on January 31, 2014, 12:19:15 PM

This doesn't prove anything. This account was created 24.11.2013. That's one and a half month BEFORE the TF was launched. I allow the possibility that the previous algorithm was right.

There was no a change in forging algo. "Transparent" added only possibility to predict next forging accounts.

Yep. And this prediction is non-democratic.

Come-from-Beyond

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Quote from: jettico on January 31, 2014, 12:27:22 PM

Quote from: Come-from-Beyond on January 30, 2014, 04:54:46 PM

For those who prefer practice, not theory:

The practice is that many thousands people are running a closed-source client and the of the main developers can't even explain explain how it works. Cheesy

I don't object the way how NXT is working now. My only point is that the TF algorithm in wiki is wrong. Maybe you just failed to describe the REAL algorithm correctly. In fact I wish it was the case Wink

Because there're a lot of other ideas in NXT that are appealing to me.

Wiki explains the algo correctly.

jettico

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Quote from: Come-from-Beyond on January 30, 2014, 04:10:09 PM

This is the problem. 100K account does have advantage over 100x 1K accounts. But this advantage is small. In ur example it's noticeable coz u use conventional dice. If u used dice with 2^64 faces u would get other results.

1) Wow! You admitted it! Now tell me how you're going to fix this.

2) It is not small. In fact it is rather huge. Consider one 100K and 100x 1K accounts:

Code:

from random import random
from operator import itemgetter

NBLOCKS = 100000
N = 100
W = [100000] + [1000] * N
z = [0.] * len(W)
wins = [0] * len(W)

for x in xrange(NBLOCKS):
for i in xrange(len(W)):
z[i] = random()/W[i]

[position, value] = min(enumerate(z), key=itemgetter(1))
wins[position] += 1

print float(wins[0])/sum(wins[1:]), float(wins[0])/(sum(wins[1:])/N)

Quote

1.71835159159 172.242506812

An wallet of 100K is 172 times more likely to forge a block than any single wallet of 1K (instead of 100 times expected) and 1.7 times more likely to forge a block than any of 100K wallets (instead of having the same probability).

That is HUGE enough to be called a flaw.

salsacz

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Activity: 490

Merit: 504

I FOUND IT!

A fatal flaw is called "FrictionlessCoin"!

jettico

member

Activity: 80

Merit: 10

Quote from: Come-from-Beyond on January 30, 2014, 06:34:53 PM

<...>
"4747" forged 13.8% of all blocks. Theoretically "4747" should have forged (50M / 1000M) * (500% / 100%) = 5% * 5 = 25% of all blocks if he forged all the time and without orphaned blocks.

"if he forged all the time "

Is it known how much time he used?
What if he used only half of the time ...
Wouldn't the expected % then be 12.5% < 13.8% ?

More statistics, plz

Those I've wanted from the beginning ...

[/quote]

All the stats r in the blockchain. Some data is not available, for example, rate of orphaned blocks.
[/quote]

First red phrase contradicts second red phrase because of the green phrase.

jettico

member

Activity: 80

Merit: 10

Quote from: Come-from-Beyond on January 30, 2014, 04:54:46 PM

For those who prefer practice, not theory:

The practice is that many thousands people are running a closed-source client and the of the main developers can't even explain explain how it works. Cheesy

I don't object the way how NXT is working now. My only point is that the TF algorithm in wiki is wrong. Maybe you just failed to describe the REAL algorithm correctly. In fact I wish it was the case Wink

Because there're a lot of other ideas in NXT that are appealing to me.

Come-from-Beyond

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Merit: 1010

Newbie

Quote from: jettico on January 31, 2014, 12:19:15 PM

This doesn't prove anything. This account was created 24.11.2013. That's one and a half month BEFORE the TF was launched. I allow the possibility that the previous algorithm was right.

There was no a change in forging algo. "Transparent" added only possibility to predict next forging accounts.

jettico

member

Activity: 80

Merit: 10

Quote from: Come-from-Beyond on January 30, 2014, 04:54:46 PM

For those who prefer practice, not theory:

Account 4747512364439223888 stats:

Balance = 50'000'000
Number of forged blocks = 7496

Nxt blockchain stats:

Total number of blocks = 54230
Average base target = ~500%

"4747" forged 13.8% of all blocks. Theoretically "4747" should have forged (50M / 1000M) * (500% / 100%) = 5% * 5 = 25% of all blocks if he forged all the time and without orphaned blocks. So we see that jettico's math is proved wrong by what we see in the reality.

This doesn't prove anything. This account was created 24.11.2013. That's one and a half month BEFORE the TF was launched. I allow the possibility that the previous algorithm was right.

jettico

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Activity: 80

Merit: 10

Quote from: opticalcarrier on January 30, 2014, 04:35:56 PM

thanks for this explanation. yes, the 'advantage' is extremely small

Why do you believe him? He didn't provide any proof!

jl777

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We are recruiting for the NXTcash team, the project to integrate zerocoin algos on top of NXT.

A key part of this is figuring out exactly what API calls we need to ask CfB to implement and any changes jean-luc would need to make to support the integration:

https://github.com/Zerocoin/libzerocoin/wiki/Integrating-with-bitcoin-clients

We know the published alpha code is slow, but we want to integrate to it in anticipation of a new improved libzerocoin2 library and to be able to release the updated NXTcash as soon as possible after zerocoin updates their code. If we can get a testnet working soon enough, I am hoping we will get prerelease versions of zerocash so we can have a chance for simultaneous release with zerocoin

We also need someone to figure out how to properly do the above integration or at least define what needs to be done where in the NXT code.

klee has put up 1 million NXT for this project. The split will be based on relative contributions

James

Come-from-Beyond

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Quote from: jkoil on January 30, 2014, 06:07:48 PM

Quote from: Come-from-Beyond on January 30, 2014, 04:54:46 PM

For those who prefer practice, not theory:

Account 4747512364439223888 stats:

Balance = 50'000'000
Number of forged blocks = 7496

Nxt blockchain stats:

Total number of blocks = 54230
Average base target = ~500%

"4747" forged 13.8% of all blocks. Theoretically "4747" should have forged (50M / 1000M) * (500% / 100%) = 5% * 5 = 25% of all blocks if he forged all the time and without orphaned blocks. So we see that jettico's math is proved wrong by what we see in the reality.

"if he forged all the time "

Is it known how much time he used?
What if he used only half of the time ...
Wouldn't the expected % then be 12.5% < 13.8% ?

More statistics, plz

Those I've wanted from the beginning ...

All the stats r in the blockchain. Some data is not available, for example, rate of orphaned blocks.

Topic: Nxt source code flaw reports - page 8. (Read 113377 times)