Cheap way to attack blockchain - page 6.

Syke

legendary

Activity: 3878

Merit: 1193

Quote from: dooglus on September 16, 2015, 12:57:24 PM

The date of a message becomes underlined if it is ever edited. If you don't edit a message, the timestamp is quite reliable. Someone with direct database access could have edited the message, but not a regular account owner.

There's a small timeframe (5-10 min IIRC) where the msg can be edited without notice.

Edited.

Previous edit at 53:08.

Edit: Ok, so the original timestamp doesn't change, but the text of the msg can change.

edric

hero member

Activity: 546

Merit: 501

Quote from: Nancarrow on September 23, 2015, 05:12:30 PM

Quote from: scriptman on September 20, 2015, 09:26:41 AM

You're not the first and you certainly won't be the last person concerning themselves with how to break the Bitcoin network.

You should use your knowledge and skills for productive means and help the community.

What exactly do you think computer security professionals DO? Or cryptologists employed by three-letter agencies? Or military strategists?

A person who wants to strengthen the bitcoin network and isn't constantly thinking of ways to break it, isn't doing their job.

I agree. But one also has to ask themselves, if it is so easy to destroy, why hasn't the government taken out the bitcoin network yet? Clearly there is an agenda behind letting it go forward. I will let you figure that one out.

edric

hero member

Activity: 546

Merit: 501

basil00

member

Activity: 60

Merit: 10

Damn, looks like Amaclin's bot stole my BTC. My tx even had a signature and everything Angry

Edit: I have a new version that uses at least one real sig

I can create an IsStandard tx that hashes >250MB, or in other words, only 5 tx to "fill" a XT 8MB block. Lucky I'm out of bits to play with.

amaclin

legendary

Activity: 1260

Merit: 1019

Quote from: basil00 on September 25, 2015, 09:21:32 AM

Interesting. What conditions are these?

Do not know. You should ask macbook-air

basil00

member

Activity: 60

Merit: 10

Quote from: amaclin on September 25, 2015, 09:18:42 AM

It was my transaction.

Yes I guessed from the 1aa... addresses.

Quote

F2Pool confirms non-standard txs under some conditions.

Interesting. What conditions are these?

amaclin

legendary

Activity: 1260

Merit: 1019

Quote from: basil00 on September 25, 2015, 09:12:26 AM

Just noticed this transaction: 324456fe9ec97a380effba0a0205a226e380790b93e7366d39f2a416a44d2a34.
2000 sigOps!.
(each OP_CHECKMULTISIGVERIFY inside the unexecuted OP_IF will count as 20 SigOps).
Also, it appears that F2Pool will mine non-standard transactions (P2SH with >15 sigOps).
It only takes 10 of such transactions to completely "fill" a block.

It was my transaction.
F2Pool confirms non-standard txs under some conditions.

amaclin

legendary

Activity: 1260

Merit: 1019

Quote from: scriptman on September 25, 2015, 09:09:31 AM

Because building something is a lot more fun than knocking it down

jedem das seine

basil00

member

Activity: 60

Merit: 10

Just noticed this transaction: 324456fe9ec97a380effba0a0205a226e380790b93e7366d39f2a416a44d2a34.

2000 sigOps!.
(each OP_CHECKMULTISIGVERIFY inside the unexecuted OP_IF will count as 20 SigOps).

Also, it appears that F2Pool will mine non-standard transactions (P2SH with >15 sigOps). It only takes 10 of such transactions to completely "fill" a block.

scriptman

member

Activity: 112

Merit: 10

Quote from: amaclin on September 20, 2015, 11:42:41 PM

Quote from: scriptman on September 20, 2015, 09:26:41 AM

You're not the first and you certainly won't be the last person concerning themselves with how to break the Bitcoin network.

You should use your knowledge and skills for productive means and help the community.

Why?

Because building something is a lot more fun than knocking it down

Nancarrow

hero member

Activity: 492

Merit: 503

Quote from: scriptman on September 20, 2015, 09:26:41 AM

You're not the first and you certainly won't be the last person concerning themselves with how to break the Bitcoin network.

You should use your knowledge and skills for productive means and help the community.

What exactly do you think computer security professionals DO? Or cryptologists employed by three-letter agencies? Or military strategists?

A person who wants to strengthen the bitcoin network and isn't constantly thinking of ways to break it, isn't doing their job.

amaclin

legendary

Activity: 1260

Merit: 1019

Quote from: scriptman on September 20, 2015, 09:26:41 AM

You're not the first and you certainly won't be the last person concerning themselves with how to break the Bitcoin network.

You should use your knowledge and skills for productive means and help the community.

Why?

scriptman

member

Activity: 112

Merit: 10

You're not the first and you certainly won't be the last person concerning themselves with how to break the Bitcoin network.

You should use your knowledge and skills for productive means and help the community.

dooglus

legendary

Activity: 2940

Merit: 1333

Quote from: amaclin on September 02, 2015, 02:33:10 AM

Quoted. Just to prove for future use (forum allows to edit messages, so the date of message does not prove anything)

Quote from: basil00 on September 01, 2015, 07:40:08 PM

Here is another hash (this time XT/BIP101 related):

Code:

d894bd6f1f8222ceb5101cc1d5d3f3eb326e04ce6b9567f74cca151bb2b7b927

The date of a message becomes underlined if it is ever edited. If you don't edit a message, the timestamp is quite reliable. Someone with direct database access could have edited the message, but not a regular account owner.

trout

sr. member

Activity: 333

Merit: 252

to mitigate such an attack, how about introducing a fee policy (min relay fee etc.) that is based not only
on the size but also on the number of SIGOPS ?

that doesn't affect the consensus, obviously.

I mean, if both the block size and the number of SIGOPS in it are a critical resource, then it's only natural to charge for using each of them.

defcon23

legendary

Activity: 1120

Merit: 1002

Quote from: speaktome on September 06, 2015, 02:43:42 PM

Wanna hire me for this dirty job? Grin

More like to somebody Gonna touch your door. Grin

Is joke of course.

pweee.. man ...

amaclin

legendary

Activity: 1260

Merit: 1019

Quote from: speaktome on September 06, 2015, 02:43:42 PM

More like to somebody Gonna touch your door. Grin

Is joke of course.

For what? I can tell you my home address.
I do not break country laws.
And there are no "laws" in bitcoin protocol. Only math and current consensus.
I can flood the network because I am able to do it. Just for fun.
(In fact, I try not to spend my time for non-profitable things)

speaktome

sr. member

Activity: 462

Merit: 250

Wanna hire me for this dirty job? Grin

More like to somebody Gonna touch your door. Grin

Is joke of course.

amaclin

legendary

Activity: 1260

Merit: 1019

Quote from: jl2012 on September 02, 2015, 04:39:58 AM

Have you heard of a project called "Bitcoin"?

Today it is immutable. But nothing is permanent under the Moon

jl2012

legendary

Activity: 1792

Merit: 1111

Quote from: basil00 on September 02, 2015, 04:23:31 AM

Quote from: amaclin on September 02, 2015, 02:33:10 AM

Quoted. Just to prove for future use (forum allows to edit messages, so the date of message does not prove anything)

If only there were some kind of immutable public ledger I could store information on...

Have you heard of a project called "Bitcoin"?

Topic: Cheap way to attack blockchain - page 6. (Read 28272 times)