FAKE or STOLEN Bitcoins

[MUFC]

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

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

[pungopete468]

You can't assign a private key to a non-existent or undiscovered coin... 

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

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

[dumbdragon]

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

[chandan123]

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

no not possible.

[Mobius7]

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?

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).

[BitOnyx]

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.

[iGROWyourBiz]

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?

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).

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

[sosulon]

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

This is the first time I'm hearing this. 

[hilariousandco]

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?

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).

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

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

[bryant.coleman]

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

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.

[iGROWyourBiz]

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

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?

[MUFC]

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

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.

What consequences are those?

[jparsley]

I dont think u can avoid stolen btc.

[bryant.coleman]

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?

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.

[zolace]

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.

[counter]

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.

[sosulon]

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

[lemfuture]

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

not yet

[dogec]

wait fake bitcoins? or stolen? two different things.