Starting point:

 - http://en.bitcoin.it/wiki/Trade#Domain_Name_and_DNS_Hosting

You started another thread?  What was wrong with the last one?
 - http://bitcointalk.org/index.php?topic=119659.0

Then GPG and the blockchain are your friends:


 - http://en.bitcoin.it/wiki/Secure_Trading#Make_sure_both_parties_agree_to_the_terms_of_the_trade_with_signed_messages

Every time I see that assertion I think of this:




With Bitcoin about $80K USD worth of bitcoins are distributed to the hashing provided by miners.   With Litecoin that is about $2K USD worth of LTC issuance.

Since each addtional GPU becomes essentially another mouth to feed it lowers the revenue for the other miners.  The reason the GPUs will be arriving is because they could no longer mine bitcoin profitably.  They won't stick with mining LTC unless it too can be done so profitably.

i.e., it soon will be time to power down your GPU rigs.

A successful cryptocurrency doesn't exist to provide an income to people who have GPUs.

The Bitcoin cryptocurrency exists because it is a way that a decentralized ledger system can exist without there being a central authority.  It does this by using consensus from an immense amount of computing power that makes it unprofitable (if not logistically all but impossible) for an actor or cartel to manipulate the currency (otherwise known as cheating or changing the rules).

If a cryptocurrency is decentralized (proof-of-work based) and is vulnerable to a single actor or cartel, it is not secure.

How would you propose this NVidiaCoin reach a point that it would be secure against this threat?

Unfortunately, about the only time an admin or experienced member can help is by providing advice before there's a problem.  

A topic on the home page of the Bitcoin wiki is titled:
 "Best practices for traders"
 - http://en.bitcoin.it/wiki/Secure_Trading

It provides suggestions that, if followed, would likely have protected you from this situation.

That wiki article contains a link to -otc Recommendations, which read:

- http://wiki.bitcoin-otc.com/wiki/Using_bitcoin-otc#Risk_of_fraud


The advice you might have received is that for a transaction in the size of $500, perhaps using an escrow would have been beneficial.  

In this instance, you would wait until your escrow partner has received (and redeemed) the Mt. Gox redeemable code / voucher.  Then you would send to Jermainé the Dwolla payment, and then Jermainé would instruct the escrow partner to release the escrowed funds to you.   Since there is no fee for using Mt. Gox redeemable codes, using an escrow intermediary adds no expense other than the fee the escrow partner charges.

The reason this helps to lessen the risk is that if your escrow is not released, you can make your case to the escrow partner who can arbitrate.   If this was an intentional scam attempt, likely the scammer would refuse to enter a trade where escrow is employed.   So for that reason, there rarely are these types of issues when escrow is used.

Additionally, there is a trust history system called the #Bitcoin-otc marketplace Web of Trust (WoT):
 - http://bitcoin-otc.com/viewratings.php

Another benefit from using the -otc WoT is that it also helps to ensure that your trading partner is really the party they clam to be.  How do you know that you really did a trade with Jermainé rather than some hacker who happened to have Jermainé's forum credentials (username and password)?   Had you used the -otc WoT, you would know it truly was Jermainé because in nearly all instances only that same person would be able to authenticate to the WoT.   (When sending Dwolla, you at least know the account number that you had sent payment to so there is some way to know after the fact whether or not it truly was Jermainé who you sent the money to, fortunately.)

Additionally, let's say Jermainé tells Dwolla that he did send to you the Mt. Gox code?  (or that he sent bitcoins or describes some other method in which he believes he completed his end of the trade?)  How will Dwolla be able to arbitrate?  (I didn't even know they would intervene ... they are a cash transfer system and you requested, electronically, that they transfer cash and that's they did ... so I would believe that their work is done.)

[Update: Additionally, Dwolla's terms of service agreement specifically reads:]


How can you prove that Jermainé didn't already give you a Mt. Gox redeemable code?  That's where the necessity for using GPG signed communications comes in.   If I am sending non-reversible bitcoins and accepting a reversible payment method like Dwolla for a transaction in the range of $500, I'm going to want to make damn sure I can prove that I really did deliver whatever it was we agreed to.   Since Mt. Gox doesn't provide the ability for a third party to see who redeemed a redeemable code, or when it was redeemed even, I don't know I would do a trade with that payment method, at least with someone I don't already have a trading history with.  At least with Bitcoin there is a publicly visible transaction ledger where if the agreement is that N bitcoins are to be sent to X address, any third party can verify that has truly occurred.

- http://en.bitcoin.it/wiki/Secure_Trading#Make_sure_both_parties_agree_to_the_terms_of_the_trade_with_signed_messages

Another recommendation is to break a transaction down into smaller parts.  The -otc recommendations read:

- http://wiki.bitcoin-otc.com/wiki/Using_bitcoin-otc#Risk_of_fraud

With Dwolla this is easy -- the fee per transfer is just $0.25.  So even without using an escrow intermediary, ... had you broken this down into four transfers of $125 each, you would be out at most $125 at this point.

Hopefully you can get this resolved with Jermainé.  Best of luck to you!

An algorithm for mining?  For the type of SHA256 hashing work that Bitcoin mining involves, there's simply an architectural difference between NVidia and AMD GPUs and NVidia performs that hashing only at a fraction of the level that the AMD architecture does.

 - http://en.bitcoin.it/wiki/Why_a_GPU_mines_faster_than_a_CPU#Why_are_AMD_GPUs_faster_than_Nvidia_GPUs.3F

So then are you are asking if there is some type of NVidiaCoin cryptocurrency where NVidia performs better than AMD?   Heh, I wouldn't be surprised if someone were to do that some day.

I'm ignorant about how a state-run lottery operates with this.  When I see people buying a ton of tickets at the convenience store how are they verifying winning status for them?  Does it involve handing them over to the cashier to be verified?

 - http://news.sky.com/story/999112/brothers-wait-years-to-claim-5m-lottery-win

 - http://en.bitcoin.it/wiki/Category:Shopping_Cart_Interfaces

The OpenCart payment module is the latest to have been updated, I believe.

What you are missing is the difference between the concept referred to as "revenue" and the concept referred to as "profit".

Revenues are cut in half.  You might be making "good profit" at a BTC/USD $12 when there are 50 BTC per block, but you might be losing your ass at $12 when there are then only 25 BTC per block.

With GPUs, it nearly entirely depends on what your cost of electricity is.  If it is low, like $0.07 per kWh or lower, you will likely still be able to mine profitably with GPU even after the block reward drop, but the wildcard is when the ASICs start shipping.

So most of the "be afraid, be very afraid" talk (which I espouse myself) is directed to those mining with GPUs who are continuing to add GPU hashing capacity at this late stage in the game.

The problem with the ASICs is nobody knows how many of the things have been ordered, how man will ship initially and from which manufacturers.


By the way, you got a free upgrade, 60 gh/s now.
 - http://www.butterflylabs.com/order-form-bitforce-sc-single/


Also, what you are missing is the concept of opportunity cost.

If you were one of the first to order a BFL SC Single back in June you then plunked down 162 BTC for a BFL SC Single  (at BTC/USD of around $8) then you don't technically break even on the investment until it has mined 162 BTC plus the cost of electricity (though this is minimal for BFL SC ASICs), plus the cost of capital (if you put that $1,299 in a bank you would have received interest on it so this investment has at least that expense), plus your time, etc.

Now let's say ASICMINER happens to go live first, and difficulty skyrockets by the time you get your BFL SC.  You'll probably wish that you still had that 162 BTC because getting to breakeven, could end up being more than a year or more away!  That's opportunity cost.  You lost the opportunity to hold 162 BTC yet today, and instead you have a claim check for a piece of hardware which is promised to yield 60 Ghash/s.

Or the bet might pay off and you are among the first to get the SC delivered and it ends up being the most profitable investment you've ever made.

The thing is, it is pure speculation at this point either way.  Nobody knows how it is going to play out.  What is known is that it is now near the end of October (the original shipping estimate provided by BFL) and ASICs don't yet exist for Bitcoin mining (from any manufacturer) as far as anyone can tell.

Along the same vein, make a copy of your wallet, and with that wallet use pywallet to delete the addresses you don't want to spend. (and -rescan after that is done)  Then it won't show the balance that included those blocks you want to keep and you can spend the remainder of that wallet.

Sorry to learn of that.


One of the ways to prevent similar scenarios from happening in the future is to study what went wrong in the past.  Could you share any of the details and any information that would describe the manner in which the coins might have been stolen?


If you need to store some bitcoins on an exchange (e.g, while performing trading or plans to do so soon), then two-factor authentication is a must!

How to use 2-factor auth on mtgox, even without a smartphone
 - http://bitcointalk.org/index.php?topic=111943.0

For most people, keeping a computer secure enough to store several thousands of dollars worth of bitcoins is beyond their technical capabilities.  As a result, cold storage likely is a more secure method to consider:

 - http://en.bitcoin.it/wiki/Cold_storage

Two-factor provides security when every withdrawal or security change (e.g., change password, e-mail address, remove two-factor, etc.) action will require a new OTP to be entered.

This is addressed in this thread:

A plea to exchanges ... lets do 2 factor right!
 - http://bitcointalk.org/index.php?topic=109424.0

If your exchange or EWallet provider claims to have two-factor but doesn't do two-factor right, let them know otherwise they'll continue thinking they are protecting their customers which can be even worse, due to having a false sense of security ("oh ya, I have two factor -- I'm safe storing even larger amounts there now!").

Here's a list of EWallets where two-factor is offered:
 - http://bitcoin.stackexchange.com/a/4114/153

You can withdraw bitcoins from your Mt. Gox account and if the address is the deposit address for another Mt. Gox account then nothing will appear in the blockchain.

Obviously, for over-the-counter trading where the blockchain is used for evidence of having made a payment should there end up being a dispute, this didn't work 100% of the time, so Mt. Gox added a checkbox labeled "Open Transaction".  When you withdraw and you mark that checkbox, then the transaction will always be sent on the blockchain, regardless if the recipient of the payment also uses Mt. Gox.

So you had it correct -- mark the block "Open Transaction" if you are using your Mt. Gox EWallet account as a bitcoin wallet and might want to track the withdrawal transaction using the blockchain.

The redeemable code / voucher is another method of doing account-to-account transfers but because they are bearer codes (redeemable by anyone who knows the code), they might not be the best tool for when performing over-the-counter trading.

Those with NVidia hardware might want to look at CoinLab's program:

Protect your future GPU mining earnings with CoinLab's 95-97% PPS Pool
  - http://bitcointalk.org/index.php?topic=99643.0


There may be other computational work developments as well.  For example:
 - http://bitcointalk.org/index.php?topic=119611.0
 - http://www.HashBounty.net


There are a lot of people in the same boat:


Small time miners - What do you do when ASICs hit and you don't upgrade?
 - http://bitcointalk.org/index.php?topic=110726.0


What will happen to all the "traditional" mines once the new ASIC based miners
 - http://bitcointalk.org/index.php?topic=114585.0

As a bookend to this thread, further discussion on the topic here:


What will happen to all the "traditional" mines once the new ASIC based miners
 - http://bitcointalk.org/index.php?topic=114585.0

Those with NVidia hardware might want to look at CoinLab's program:

Protect your future GPU mining earnings with CoinLab's 95-97% PPS Pool
  - http://bitcointalk.org/index.php?topic=99643.0


There may be other computational work developments as well.  For example:
 - http://bitcointalk.org/index.php?topic=119611.0
 - http://www.HashBounty.net
 - https://vanitypool.appspot.com/faq

[Edited:  Added Vanitypool mining.]

Well what is the "best data" from your perspective might be different from your customer's perspective.

Here's an excerpt from a related conversation:

This morning I deposited a $20 at my bank.  Later in the day a friend of mine withdrew cash and got that exact same $20 bill that I had deposited (let's say I had written down the note's serial number).  Does that mean "money is leaving my account" at my bank?  If not, then why not?

Your account at Mt. Gox is just like the account at a bank.  It records deposits and withdrawals and shows a balance.  The blockchain cannot be used to monitor your balance of your Mt. Gox account.

If you have a PayPal debit card, sure.  Sure.  You can take that debit card and go visit an ATM and withdraw cash.  Then use that cash to buy bitcoins.   Then cash out those coins at AurumXChange and withdaw Liberty Reserve.

Methods for buying bitcoins with cash include:

Options:
 - http://www.BitInstant.com (Deposit at major banks, 7-11, Walmart, CVS, Moneygram, etc.,)
 - http://www.BitMe.com (Deposit cash at Chase)
 - http://www.BitFloor.com (Deposit cash at Chase or Wells Fargo [temporarily unavailable])
 - http://www.MrBitcoins.com (Deposit at a bank in U.S., India, Australia)
 - http://www.CAVirtEx.com (Deposit cash at several banks)
 - http://www.Spendbitcoins.com (Deposit cash at a bank in Australia)
 - http://BitcoinNordic.com (Purchase CashU or UKash in dozens of countries)
 - http://www.BTC-E.com (Deposit cash (USD) at bank locations in Russia)
 - http://www.BitNZ.om (Deposit cash (NZD) at back locations in New Zealand)
 - http://www.BitInstant.com (Deposit cash in Brazil using Boleto or Banco Recomendito, or in Russia, using Qiwi or Cyberplat.)
 - http://www.VirWoX.com (Purchase UKash in dozens of countries with cash, then buy SLL and trade them for BTCs)
 - http://www.MercaBit.eu (Purchase UKash, Paysafecard, and others with EUR cash)

Also, Bitcoins Direct will accept cash, but they have a $500 minimum order size:
 - http://bitcointalk.org/index.php?topic=87094.0 (Deposit cash at Bank of America, Wells Fargo or PNC, minimum $500)


With a PayPal debit card  and being in the U.S., you might be able to buy coins through:
 - https://www.quickbitcoins.net


Another method, from anywhere, is to use credit card to buy SLL (Second Life Lindens) through VirWoX, and then trade those for BTCs:
 - http://www.VirWoX.com


There are quite a few methods:
 - http://en.bitcoin.it/wiki/Buying_bitcoins