A guy insisted on buying my private key instead of an actual transaction - why?

[gabriella]

i had 50 btc to sell and i advertised. a guy contacted me and offered to buy at slightly higher than market price.

the only condition he insisted was that we would trade the private key instead of the actual btc over the network.

i said fine, i moved 50 btc to a newly generated address and printed out the private key.

we met in a public place, he showed me the dollar bills, i showed him the private key.

we checked there is the right amount of btc at the address linked to that private key, we shaked hands and parted ways.

lated i checked the balance of that address and every btc has been moved to a new address.

i am curious - why did he do that?

[DeathAndTaxes]

No idea.  He probably (incorrectly) thought it would somehow be more secure or less traceable.

[franky1]

the less a coin moves (less transactions) the cleaner it is so by taking the private key and not sending the coins via a transaction, saves on the movements a coin makes

i know people that would love to have a private key that contains coins that are only just mined or have only moved 1 hop from a mining pool. the people that want this are the paranoid people that think if they have a coin that has passed through 3 peoples hands before reaching them, and then they use it in a crime. they think the authorities can search out the previous owners ( if they advertise their keys) and then get them to admit who they dealt with.

but a private key that just shows 'virgin' coins is considered precious.

[DeathAndTaxes]

the less a coin moves (less transactions) the cleaner it is so by taking the private key and not sending the coins via a transaction, saves on the movements a coin makes

i know people that would love to have a private key that contains coins that are only just mined or have only moved 1 hop from a mining pool

Except he did move the coins.  Not moving the coins would be an asinine security risk as the owner could simply take them back at any point until they are moved.

[StarfishPrime]

Or he was just a middleman. A private key on a slip of paper can change hands many times without ever touching the blockchain.

[DeathAndTaxes]

Or he was just a middleman. A private key on a slip of paper can change hands many times without ever touching the blockchain.

I guess but very risky.  When the tx was done the OP could have sent the coins to a new address.  Proving it was the OP not the middle man who moved the coins after the fact would essentially be impossible.

[beetcoin]

that sounds way too risky. OP could have just made a backup, sold him the private key, rush home and then send the coins to a new address.

the less a coin moves (less transactions) the cleaner it is so by taking the private key and not sending the coins via a transaction, saves on the movements a coin makes

i know people that would love to have a private key that contains coins that are only just mined or have only moved 1 hop from a mining pool. the people that want this are the paranoid people that think if they have a coin that has passed through 3 peoples hands before reaching them, and then they use it in a crime. they think the authorities can search out the previous owners ( if they advertise their keys) and then get them to admit who they dealt with.

but a private key that just shows 'virgin' coins is considered precious.

sounds like unhealthy paranoia.. LE would have a hard time pinning certain transactions to a user especially since coins are/can be tumbled.

[philip2000uk]

i had 50 btc to sell and i advertised. a guy contacted me and offered to buy at slightly higher than market price.

the only condition he insisted was that we would trade the private key instead of the actual btc over the network.

i said fine, i moved 50 btc to a newly generated address and printed out the private key.

we met in a public place, he showed me the dollar bills, i showed him the private key.

we checked there is the right amount of btc at the address linked to that private key, we shaked hands and parted ways.

lated i checked the balance of that address and every btc has been moved to a new address.

i am curious - why did he do that?

he might say that the key was stolen and someone took it, to make you give him another 50 for free