Bitcoin Forum

Is it possible for someone to give me fake or stolen bitcoins?

How long do I wait to make sure a BTC is "legit" and truly mine?

fake bitcoins ?  ???  :P

The closest known way is to double spend bitcoins.
As far as stolen bitcoins, you will almost certainly touch them.
With Mt.Gox having stole so many and the silkroad bust having stole many, LOTS of stolen bitcoins.
It would be wise to wait for at least one confirmation.

What the fuck is this guy talking about?

Stolen bitcoins exist but if you're paranoid then use a mixer or gamble them and get clean coins back.

Fake bitcoins would be no fee bitcoins which are basically fake since you never get them cause the miner fee wasn't paid.

I hope this helped?

You are wrong, fake bitcoins doesn't mean bitcoins without fee. There is nothing such like fake bitcoins, only way would be double spending. Just wait for confirmation, and it would be fine.

They would be fake because he sees the transaction but it doesn't confirm. That's fake in the sense they're not real. You get it?

Are you afraid that someone would give you dirty coins (i.e coins stolen from someone else)? Not much can be done about that. Stolen Bitcoins are extremely difficult to track.

so many virtual wallets etc.

i am just thinking purloined or counterfeited.

It just math right?  What stops the evil genius 8 year old from hacking his xbox1 and pc to figure a way to "steal" coins.

Is it only improbable or is it truly impossible?

Truly impossible until someone actually does it.  :D

I suppose if you are using Bitcoins on a third party website like an exchange, gambling site, etc... You could have a Bitcoin balance higher than the actual coins owned by the website.

As far as sending fake Bitcoins across the Bitcoin network; no. It will not happen. If you were to look at the mathematical statement of 1+1=2 you would know that this is correct. When you add 1+1 you will always get 2.

Every Bitcoin in the Bitcoin network exists within the blockchain and not within any wallet. They don't move anywhere...
When you send coins, you aren't sending the coins. You're updating the private key for those coins. The coins never moved; the private key to those coins was simply changed and the owner of the new private key is the recipient.

So you can't send fake coins anywhere. You can't assign a private key to a non-existent or undiscovered coin... 

You just need to wait until the Bitcoins are fully confirmed. Then they're yours to spend or keep as long as you want. And yes, somebody could send you stolen Bitcoins, but there's probably some fiat coins or notes in your physical wallet right now that have been stolen or got 'dirty' somewhere down the line.

What does that guy mean ?  ???

It's like people giving you stolen cash to pay for products?

Yeah, I think he just means if someone hacks somebodies wallet or scans them then he ends up buying the coins somewhere down the line.

It is rare and hard to fake transactions so I wouldn't even bother going there. As far as stolen coins - you're bound to get some at some point and just like stolen cash back in the system you can't tell the difference.

There won't be any fake BTC, its my opinion

Yes, as allready said, it is possible. Same as it is possible that the person in front of you at the supermarket line stole the cash and the cashier gives it to you as change. But even IF you get stolen coins, as long as you got the legitimately, you dont have to fear anything.

Now how long do you have to wait. While bitcoin core suggests you to wait for 6 confirmations in the network, Im usually fine with only 2 when I get payment <1 bitcoin. If you feel insecure about this, wait for 6 confirmations.

Since Bitcoin is a currency that was designed to change hands often, there is always a chance of receiving stolen Bitcoins. That shouldn't be a problem though, provided that you didn't steal them yourself. Bitcoin is money in digital form -- that's all it is. As for "fake Bitcoins," that's not even a real thing. An unconfirmed transaction doesn't make a Bitcoin fake. Just wait until the transaction is confirmed, and barring the possibility of a double spend attack resulting from a forked blockchain, then those Bitcoins should be yours until you spend them. The general rule of thumb is to wait for 6 confirmations (roughly 60 minutes) before considering the transaction as fully confirmed.

don't worry, bitcoin is more or less anonymous and no one will do anything bad to you if you accidently acquire some coins with a dirty past :D

You cant do anything about receiving stolen coins, but they can't be faked as that's one of the benefits.

so i can't (purposefully/randomly) determine the "next key" or stumble on an undiscovered coin?  or rather "soon-to-be" discovered coin?

I think that's a big benefit compared to the amount of fake fiat money.

nope. That would be like solving the answer to the secret of life, the universe, and everything.

This is the first time, I heard someone having a fake bitcoin. Is that even possible??

no not possible.

There is no "fake" bitcoin. As long as your transaction gets a few confirmations, no one including the sender can reverse the transaction (unless in 51% attack).

There can't be fake bitcoins .

Stolen ones is different problem, but not to the point you should worry someone would take them away from you.

sorry for my ignorance - but what is 51% attack?

This is the first time I'm hearing this.  ???

Where the miners have 51% of the power: https://bitcointalk.org/index.php?topic=569967.0

Be ready to face the consequences if you are ready to accept stolen BTCs. Especially this will be the case, if you accept dirty coins stolen out of SR 2.0 or the Sheep Marketplace.

Bryant - you are touching on my concern

As a business man, I deal with enough money to know that I may have IGNORANTLY accepted stolen money in small amounts.  That is understandable.

HOWEVER, I HAVE A DUTY to TAKE PRECAUTIONS against suspicious transactions and to purposefully DENY money I KNOW to be stolen.

HOW COULD KNOW if a BTC is stolen or not?

What consequences are those?

I dont think u can avoid stolen btc.

Understand your concern. If you are a merchant, you will be using a Bitcoin payment processor such as Bitpay. There is very little chance of such coins getting through Bitpay. Even if (extremely unlikley) you get stolen coins from Bitpay, it is their fault, not yours.

As others have said "copying a bitcoin" is trivial but of no value.

Your wallet consists of addresses and each of those addresses has a certain value.

When your wallet says you have "20 bitcoins" it simply an abstraction. Currently your wallet file consists of multiple addresses and the combined value of those addresses according to the bitcoin block chain is 20 bitcoins.

When you transfer bitcoins to someone you don't hand over "a bitcoin". You submit a transaction to the network. The network makes sure your address is valid and has the proper value. So there is no risk of counterfeiting because there is nothing to counterfeit.

There is a risk of double spending. When I transfer bitcoins from me to you the network prevents me from doing it again (and again and again ...). When you submit a a transaction the network verifies that each transaction is valid before including it in the next block.

IF hypothetically you had enough computing power you could cheat. You could include your invalid transaction in the block and sign it as valid. The strength of bitcoin comes from the size of the network. Currently ~17Thash/second. An insane amount of computation power. As long as the network remains large enough and diverse enough that one entity can't control 51% there is very little risk of double spending, so long as the recipient waits for a confirmation.

Well if you mean in person which I'm thinking you don't then yes it is possible.  As for sending to you over the interenet no there is no way they coins are fake..  Stolen however is a whole different matter.

Is there a method to determine if a coin is stolen or not

not yet

wait fake bitcoins? or stolen? two different things.