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1  Bitcoin / Bitcoin Discussion / Re: [LIVE] Withdraw Your TradeHill Balance Instantly- BitInstant on: February 25, 2012, 04:29:47 AM
How long does the Tradehill->Mtgox transfer is supposed to take? I made a transfer yesterday, the funds were gone by today morning but still nothing in Mtgox.
2  Bitcoin / Development & Technical Discussion / Re: Different version, different difficulty (0.3.20.2 vs 0.3.24) on: August 01, 2011, 01:08:13 PM
i guess the 0.3.24 number is more correct since it's a later version, but why is the older one therefore wrong?

The algorithm for calculating the printed difficulty was slightly inaccurate and was changed for a correct one. Since the printed difficulty is for humans only, it's not a big deal.

The discussion is here:

http://bitcointalk.org/index.php?topic=10002.0
3  Bitcoin / Bitcoin Discussion / Re: Camp BX - Affiliate Program Announcement on: July 08, 2011, 10:52:33 PM
These affiliate programs (in all exchanges) are a nothing more than a huge waste of time. Waste of time for creating multiple accounts and reading those spammy messages on threads. Any rational person would create two accounts, one for making a referral link and other for trading. This way, one can get twice the 10% discount. No rational person should use a third-party referral.

You could save us time and just lower the commission.
4  Bitcoin / Bitcoin Discussion / Re: Pools Owning About 50% of The Hashrate: A Realistic Attack Taking 2 Hours on: July 07, 2011, 10:17:24 AM
Personally, I would urge exchange owners to require 144 or 288 confirmations (nominally 24 or 48 hours).

It is definitely too draconian. Imagine there is a sudden jump in BTC value and you want to cash out. Sorry, 24 hour waiting.

The exchanges can, however, instate a 24 hours waiting period for cashing out. Essentially, you could withdraw balance that was there 24 hours ago. If there is a BTC reversal, the perpetrator would have a negative BTC balance in the exchange account. The USD balance that is hold for 24 hours could cover the loss then.
5  Bitcoin / Bitcoin Discussion / Re: Pools With a Significant Hashrate: A Realistic Double Spend Attack Taking 2 Hr on: July 07, 2011, 08:41:57 AM
The hash of the "previous block" in the getwork reply is actually completely opaque data to a pool miner, who cannot verifies whether it is legitimate or not. One reason being that it varies based on unpredictable data that is known by no one else but the pool owner (eg. the 50 BTC generation fee transaction).

Getwork returns data (essentially block header) and midstate. Midstate can be created from data. Data contains block header which MUST contain previous block hash. Block header contains also merkle root which is unpredictable but everything else must be consistent.

Hash is unpredictable but the data to be hashed must be valid. Otherwise the block will not be accepted by the network.
6  Bitcoin / Bitcoin Discussion / Re: Pools With a Significant Hashrate: A Realistic Double Spend Attack Taking 2 Hr on: July 07, 2011, 07:59:01 AM
When you are in a pool, you only get pre-hashed data. You can't see anything you are working on.

OK, I have not used pools for a long time but if they return a valid getwork (and they should), then getwork returns the block header. The hash of the previous block is there.
https://en.bitcoin.it/wiki/Block_hashing_algorithm

Pools only need to manipulate the target hash so the miners submit all the hashes of difficult 1 and above
The attacker may try to spoof the data block, but then the hash of the data would differ from the midstate.
7  Bitcoin / Bitcoin Discussion / Re: Pools With a Significant Hashrate: A Realistic Double Spend Attack Taking 2 Hr on: July 07, 2011, 07:47:51 AM
This whole attack is possible but is not undetectable. The pool miners will know they are not working on the main chain. However, most of the miners will have no idea and the miner programs will not print it automatically.

The hash of the previous block is contained in the getwork data returned to the miners. If the miner program does the getwork to the local copy of the bitcoin daemon, it can compare the hashes and print warning. It happens occasionally though (some accidental chain forks), however if it happens twice in a row (chain fork differs by two blocks), it is very unlikely by accident and very likely by an attack. It does not seem to be very difficult to program into the miners as an option to print warning and better yet to switch to another pool if it is happening. If large enough number of pool miners switched, the attack would be prevented.
 
8  Bitcoin / Bitcoin Discussion / Re: If an attacker gets more than 50 % of mining power on: July 01, 2011, 12:05:31 PM
To reverse a 1000 blocks and to catch up then to make the longest block chain takes way more than 50 %, if you want to get it done in a decade.

If you have more than the rest of the network combined (so more than 50% of total power including you), you can grow the alternative chain indefinitely as long as you are ahead. If you have 1% more than the network, you will be 1.44 block ahead per day. If you have 10% more, you will have 14.4 blocks per day. If you have twice the current Bitcoin network, you will reverse 1000 blocks in less than a week.

If you want to do as much of a mess, grow your chain, and wait until the rest of the network caches up with the speed. And then release the alternative chain.

9  Bitcoin / Bitcoin Discussion / Re: Fees - do they work? on: June 30, 2011, 01:28:18 PM
There were quite a few threads that discussed this problem. E.g.,
http://forum.bitcoin.org/index.php?topic=6284.0
http://forum.bitcoin.org/index.php?topic=8126.0
http://forum.bitcoin.org/index.php?topic=9162.0

The were two camps:
1. The market will solve all the problems
2. Yes, but with a not too pleasant outcome for bitcoiners.
10  Economy / Economics / Re: What gives a fiat currency its initial value? on: June 30, 2011, 09:35:16 AM
Contrary to the posters above, it is always the market the sets the value.

Historically, during gold/silver standard, currencies were just a title to some weight of gold or silver. The value of currency was linked to commodities value.

Currently, when currencies are not backed by any commodity, it is also the demand and supply of money that sets the price. The supply of money is to some extent (but not completely) controlled (one may say "manipulated") by the central bank, by the demand is not and the market entities decide whether it is worth to hold the currency given this price or not based on interest rates, central bank/government trustworthiness, economy situation, etc. Sometimes central banks try to fix the value of currency (or rather fix it relative to something else). That can be successful if the supply side of the money is carefully controlled. But if the market value would have been different, quickly a black market will appear with a different price.
11  Bitcoin / Mining / Re: Impact on GFX manufacturers? on: June 26, 2011, 09:10:48 PM
however the high end market is a drop in a bucket compared to overall GPU sales when it comes to number of cards sold.

On the other hand, high-end market has much higher profit margin and Bitcoin-related sales will be a bit more than a drop in the bucket profit-wise.
12  Bitcoin / Bitcoin Discussion / Re: How many with the account stil locked at MtGox? on: June 26, 2011, 07:25:06 PM
FYI. I finally get the password reset email and the account is working now.
13  Bitcoin / Bitcoin Discussion / Re: How many with the account stil locked at MtGox? on: June 25, 2011, 06:22:43 PM
Account claimed. Password doesn't work. Password resetting email did not arrive. Opened ticked is not answered. I'm stuck in a limbo.
14  Economy / Service Discussion / Re: Password Recovery does not work on MtGox on: June 25, 2011, 04:14:36 PM
I'm stuck, too. I didn't even get any email from password resetting on the claim page.

I opened a ticked 10 hours ago. No reply.

All this even though I'm pretty sure I'm entering the correct password because I wrote it down.
15  Bitcoin / Bitcoin Discussion / Re: MT GOX - Account-Tool - Not working..? on: June 25, 2011, 01:34:50 PM
I had a long password and couldn't login. This may indeed be the pattern.
16  Bitcoin / Bitcoin Discussion / Re: MT GOX - Account-Tool - Not working..? on: June 25, 2011, 06:11:00 AM
Same here. "Error in login or password" with both new and old password.
17  Economy / Economics / Re: BTC hit 120 PLN, (217/156 as valuable as MtGox high) - did anyone notice? on: June 22, 2011, 04:58:24 PM
Anyone know what kind of fees the websites that use PLN charge?

Currently: 0% trade. 0% deposit. 0% withdrawal.
18  Bitcoin / Bitcoin Discussion / Re: DIRECT DOWNLOAD LINK FOR LEAKED MT. GOX ACCOUNT DATABASE (CSV FILE) on: June 20, 2011, 01:18:52 PM
The salted crypt() hashes are more difficult to crack but so far I have found 2706 out of 59236 passwords of the database by just one hour GPU dictionary-based cracking.  It can be safe to assume that the attacker was able to crack similar number and could control thousands of accounts.
19  Bitcoin / Mining / Re: Please bail me out - I'm an idiot bought mining gear at the peak on: June 18, 2011, 07:54:47 AM
Unless BTC rate crashes really hard, you are not going to lose money. You may not earn much at all above your costs but mining is still fairly profitable:
http://bitcoin.atspace.com/income.html
The good thing is that if the profitability drops, difficulty increase slows.
20  Bitcoin / Bitcoin Discussion / Re: My proposal for AllinVain's theft. on: June 17, 2011, 07:09:42 AM
Or even if they do use so called 'strong password' they'll easily get cracked by a GPU based password cracking program. These days even 11 to 20 character length password aren't safe.

Now you are exaggerating. If you don't use dictionary words and preferably you use a random combination of alphanumerics, 15 character long password is uncrackable brute force. Even whole Bitcoin network would not brake it. My back-on-the envelope estimation is that such a randomly chosen password would need more than million years on all the GPUs on Bitcoin network. I think we should worry more with weak password and trojans.
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