https://www.bitaddress.org

Click on paper wallet.

What SgtSpike said but I think it will be more like 10x to 20x in the short term and probably much much higher than that in the long run (100x to 200x is certainly not impossible).

Right now looking at difficulty (which is based on the economics of GPU cost, wattage, etc) and applying it to not yet produced ASICs is just as flawed as looking at CPU difficulty and assumming it would remain the same when GPU miners hit.  In July 2010 it is unlikely anyone was GPU mining.*  Difficulty was ~20 (no not 20 million, 20).  Six months later it was ~10,000. Six months after that it was ~10,000,000.  Will ASICs do the same thing?  Probably not to that magnitude (there were other factors which pumped difficulty up in late 2010) but it shows you the risk involved.

http://bitcoin.sipa.be/speed-ever.png


* The first public release of a GPU miner was in Sept, 2010 although there are rumors that some were GPU mining in private.  The near vertical rise in difficulty from July to August would seem to suggest that is true.

Huge amount of risk for likely very little profit (or potentially a loss).

Say the return on the asset is 10% a year.  Lets ignore the exchange fees, bank fees, wire fee, lawyer fees, etc.  Lets also ignore the tax implications on the holding company, the potential for ebezzlement, gross mismanagement, etc. 

In USD terms the asset produces a 10% return, however (hypothetically) the BTC/USD exchange rate rises 20%.   In BTC terms the value of the shares will decline 20% and the dividend paid out over the year will only be 10%, resulting in a net loss for investors compared to simply holding BTC.

Add to it the illegaility of issuing unregistered securities (in the US and most other "first world" nations), the risk of the operating disappearing, and the normal business failure risk and it starts looking like a lot of risk for not much return.

The probability of a double spend under that scenario is essentially nil.   Bitcoin doesn't need to be 0% fraud it just has to have a transaction cost (equipment, fees, fraud losses, etc) that is lower than the alternatives.

Nobody is going to attempt to double spend fast food purchases.

1) It is low value, hard to control/time, and in person.

2) Even if you and another party did try to engage in a simultaneous spend fast food isn't "instant food" it takes what 1-2 minutes from the time you pay until you receive the food.  Anything longer than 15 seconds and the probability of a non-finney double spend is essentially zero. Most likely the merchant will leave the implementation details to a payment processor.  The payment process would use the time between payment and delivery to look for double spend attempts.

3) If you want free food it would be easier to just use a stolen credit card.  When is the last time you were asked for ID or even had you sign a receipt when getting fast food?

$0.05 by the end of the week ....  

$0.05 per mBTC that is.

D&T troubleshooting guide.

The battery turns the starter.  If there was an issue with gas line, or fuel injectors, or flux capacitor the battery would still turn the starter.  It would turn the starter quickly and promptly but the car wouldn't start.

"click click click" or "wrug, wrug, wrug" or hearing starter turn but slower than you normally remember it, or gauges doing "weird crap" when trying to start, or "nothing" = electrical most likely battery but it could be any component in the electrical system (to include starter motor)  Make sense?  Frozen gas line or other problems wouldn't prevent the battery from powering the starter motor.   See you narrowed it down from the "entire car" down to the electrical system (80%+ potential problems eliminated).

Most likely (90%) you have one or more dead cells in the battery.  It isn't just drained it is "BROKE".  Replace the battery.  The auto parts store will be able to get you the exact size you need.  If you plan on keeping the car more than three years pay a little more for a better battery (store will give you two or three options).  Get a brush to clean the terminals and some corrosion resistant pads (auto parts store will know).  Even if you had to buy a cheap socket set it will still be $50-$100 cheaper than a garage.  Note: save your reciept and bring the dead battery to the store.  There will be a "core charge" which is refundable when you turn in  the "broke" battery.

c4n10 did you even read your own link?  It is a really good resource, you found it and then it looks like you ignored it.  There are two classes of chargebacks.  One is 60 days from the date of the billing statement (which could be up to 90 days from the purchase).  The second class is 365 days from the date of the billing statement.  It is right there in your own link.   Also those are the minimum required by federal law, nothing prohibits credit card issuers from allowing chargebacks beyond that.  Many credit card issuers allow more generous terms or are willing to waive the limits if a customer just misses the cutoff.  Why?  Their customer is the person doing a chargeback.  The last thing they want is Joe Consumer to feel "ripped off" and transfer his balance (and all those never ending interest payments) to a "fairer" card, especially not the kind of consumer who has a good job, racks up a huge balance, makes the min payment on time each month, and simply revolves it until he/she dies.  They give two flying craps about the poor merchant getting slammed with bogus charges.

The point is to be safe you need to wait at least 90 days and even that doesn't guarantee it.  Now the reality is most scammers are going to do a chargeback pretty quick probably within days (maybe a week if they want to hit a site multiple times first), however in the case of truly stolen cards most of the time the victim isn't going to notice until after they get the statement and get around to reading it so say 30-45 days after the purchase.  

Hey I am looking to sell my used 2016 Porsche too.  Make me an offer.

Honestly this.

If you are a hardcore gamer then buy the best AMD GPU for gaming and consider anything you get from mining as a gift.   Buying GPU for mining today is a good way to take a pile of cash and light it on fire.  You have absolutely no hope of breaking even much less showing a profit.

The purpose of crypto-currency is to allow two parties to engage in commerce without needing to trust a third party.  The blockchain and mining is the compromise necessary in order to eliminate the trusted third party (central authority) There is no point in making a cryptocurrency that requires a trusted third party.  You can simply have the central authority use an internal accounting ledger and not need to waste any energy on mining, a blockchain, or transaction processing.  

There are plenty of digital payment systems which use a trusted central authority.  PayPal and Liberty Reserve would be two examples.   Without a controlled supply you can't peg to a currency.  If demand exceeds supply for "poundcoin" then people will sell them for more than a pound.  If supply exceeds demand then they will sell for less than a pound. 

Two confirmations is better than one because to reverse the tx an attacker would need to make a longer chain and the more confirmations that a tx has the further back the miner would need to go to produce the longest chain which doesn't include the tx.  If a tx has 2 confirmations to be reverses an attacker would need to produce 3 blocks before all the good miners combined make 1.  If the attacker only makes 1 or 2 he is still behind.  60 blocks is better than 2 because for an attacker to attempt to reverse this would require making 61 blocks before all good miners combined can make 1.  This is essentially impossible unless an attacker has 51% or more of the global hashing power.

I think somehow despite two dozen explanations you don't understand what a confirmation means.

Say the most recent block is 10009.

(unconfirmed tx)
Block 10009
Block 10008
Block 10007
Block 10006
....
Block 1
Block 0 (genesis block)
 
If your tx is not in the blockchain it is unconfirmed (0-confirms).  If your tx is in block 10009 (the most recent) then it has 1 confirmation.  If your tx is in block 10008 it has 2 confirmation.  etc.

Neither each will broadcast their block to their peers and those peers will build off that block.  Temporarily the network will be split some miners building off block "a", some building off block "b".   Eventually one side will solve the next block and the other chain will be orphaned.

Example:
current block  is 1000
Miner A produces block 1001a, Miner B produces block 1001b.  Part of the network believes block 1001a is the correct block, part of it believes 1001b is the correct block.
Eventually someone will produce block 1002.  If block 1002 builds off block 1001a then 1001b will be orphaned and all miners will build off block 1002 to produce 1003, 1004, etc.

Simple version is no.  There is no such thing as a "fake" block.  Either the block is valid or it is invalid.  An attacker could broadcast invalid blocks on the network, however it is trivial to validate a block.  The average CPU can validate a block in a fraction of a second so it isn't much of an attack.  No miner is going to build upon a block until they validate it.  If the block doesn't validate it will be discarded.  

Um he can't trust the 0-confirm transfer from a private key known by someone else. You could already be racing him to the next block in a double spend using that private key, or created a tx with a massive fee attached to tempt irreputable miners, or used your own hashing power to perform a Finney attack.

Shared Private Key = EXACTLY SAME LEVEL OF SECURITY as 0-confirm tx on the blockchain.

Please don't share misinformation which could result in someone losing funds to an attacker.

You misunderstand.  If SHA-256, RIPEMD-160, and ECDSA are never (as in not today, not next century, not 489230824390248390 years from now) compromised then your right lost vs not lost would be the exact same (essentially 0%) chance.

However the more plausible scenario is that RIPEMD-160, SHA-256, or ECDSA will eventually be compromised and while it will be difficult to brute force (think mining but for existing coins) it will be possible.  Long before that theoretical attack becomes useful a NEW bitcoin address type based on NEW stronger algorithms can be created.  Over the course of years (potentially decades) coins would be moved to these new addresses.  Given the increasing risk of losing ones coins it is very likely the only coins remaining in "version 1" addresses would be the ones which can't be moved because the private keys have been lost.

Right.  Technically if there was some "slow" users who didn't upgrade their "not so lost" coins could be treasure hunted too.  However based on prior cryptographic breaks we are probably talking about a timeline in years if not decades even after a credible flaw is found.  More than enough time for even the most clueless user to move to new address types. For example although SHA-1 is considered cryptographically broken if Bitcoin addresses used SHA-1 it would still be uneconomical to brute force.  Estimated cost to produce a single collision is roughly $2.7M USD using rented cloud computing time.  The original flaw in SHA-1 was found in 2005 based on a known flaw from SHA-0 found in 1998.  

http://www.schneier.com/blog/archives/2012/10/when_will_we_se.html

The interesting thing is that if/when that happens we will get the first good estimate of the number of truly cost coins. 

There is a small chance lost BTC can be found if the cryptographic algorithm protecting current addresses eventually is compromised to the point that "treasure hunters" can brute force existing addresses.

This.  Bitcoin won't survive a global EMP, the internet won't, the modern world won't, hell even current nation states won't.  Integrated circuits are in everything.  A hundred million people will die almost instantly billions as society breaks down.  Some from the initial failure, lots more from starvation and disease, and violence and war.

Imagine an EMP powerful enough to warrant a paper blockchain hit globally right now.  The first thing is that the internet is toast.  Not just your PC but hundreds of billions of dollars in switches routers, network interconnects, datacenters, etc.  Gone.  Turned into scrap metal.  Rebuilding isn't going to be easy.  Guess what is used in semiconductors FABS?  Yup integrated circuits.  The FABS that build computer chips need computer chips which will also be destroyed.  

Ok so we can live without computer right?  Well it goes way beyond computers.  Integrated circuits are a critical component of everything from communication systems, to the electrical grid, to transit systems, to the water supply.  They will all fail massively, catastrophically, and simultaneously.  Planes will literally fall out of the sky, and every major highway in the world will turn into a parking lot but not before killing tens of millions of people.  The electrical grid will acts as an giant antenna and huge amounts of current will cause it to tear itself apart.  If lucky, nuclear powerplants will SCRAM hard and be idle for a lifetime, and if unlucky will meltdown due to a combination of uncontrolled decay heat and widespread equipment failures which overwhelm even triple redudant systems.  The imbalanced grid will collapse and the world will go dark except for the electrical fires everywhere, from destroyed transformers, and powerplants.  Restarting it will be impossible without replacement parts on a scale never seen in the history of mankind.  

All that will happen almost instantly but the failure of society will take longer.  If you have any pressing medical condition more complex then setting a broken bone your fate is probably already sealed.  With the transit systems down hospital will run out of supplies quickly and then people will start dying like they did two hundred years ago. Once the fires start they will burn out of control.  What are fire departments going to do?  Send fire trucks down miles and miles of streets clogged with cars that won't start?  Get water out of fire hydrants with no functioning pumps.  Whole cities will burn to their foundations.

The big killers will be starvation and disease.  Cities will become graveyards in a matter of weeks.  The average urban area only has enough food to feed the population for a couple weeks.  That is everything, the food in homes, in stores, and in distribution centers. With transit, electrical and water systems in ruin the never ending stream of consumables into a city will stop, as will the never ending stream of waste out.   Without a functional water system,  lack of sanitation means age old killers like dysentery will burn through the populace (weakened by malnutrition and over reliance on antibiotics) like a biological weapon.  

Governments will try to restore order but it will require martial law.  I don't mean call out the national guard because there was a hurricane I mean executing "enemies of the state" by the tens of thousands in the street.  It won't be enough though at least not on any large scale, although pockets may maintain some level of order in a police state.  Modern nationstates with hundreds of millions of people can't survive on a pre-industrial technological base.  Troops and police will desert by the thousands to return home and protect their families.  

The strong will band together and take resources from the weak.  Our modern society can't survive significant supply disruptions so for the first time in a century there really won't be enough to go around.  Not enough food, not enough water, not enough scarce resources (medicine, shelter, good tools, etc).  The strong taking from the weak ensures some will die but some will survive.  The surviving people will abandon the urban areas (graveyards) that are a product of a technology base which no longer exists and move back into rural areas. The human race will survive and in time society will rebuild itself starting back at city states (a stable political structure which can operate at a minimal technological level).

If anyone finds a surviving printed copy of the blockchain (under the corpse of some nerd who's skull is caved in by a cinderblock) they will either use it to wipe their ass or burn it to stay warm.

Nope, Bitcoin won't survive a massive (and unlikely) global scale EMP or other end of the world type event.   Bitcoin can survive temporary outages but it is a product of a computer aged civilization and if that civilization dies so will Bitcoin.


Maybe in a couple decades or a century after the event.  In the short term your dilemma is easily solved.  The guy with the gun puts two rounds into the chest of the guy with the water and now the guy with the gun has a gun AND water.  

Little known fact the Pyramids are the blockchain from an even earlier genesis block. Trust me you didn't want to be a slave in Egypt when there was a blockchain re-org.  Brutal!

Wow.  That "press" article wins the award for "stupid of the day".

Who knew buying something with your bank card or PayPal account (which has been opened with name, address, social security number, and possibly credit check, etc) is instantly private as long as you use TOR.  

Someone should let the SR know.  BANK WIRES, CC, ACH, hell Direct Deposit from your employer + TOR = insta privacy shield.   I am sure the DEA is going to be pissed this reporter let the best kept secret out of the bag.

Hee hee hee.  Thats funny.

https://btc-e.com/exchange/nmc_btc

Let me try.  WTT 3 candy bars for 1 gold bar.