How do you transfer Bitcoins without an Internet connection?

[Prophet]

We have had the examples from the banks since ancient times: denominated currency devised into useful amounts. You have a licence to print your own money. Have we not become our own banks thanks to this technology?

Begin printing BTC1 .50 .25 .125 .0625 .03125 .015625 or any subdivision you can think of, the key is that no transaction would ever need to go through the system if we exchanged barcoded paper denominations of bitcoin; like proof that you have btc in the bank redeemable at anytime over the network.

Just imagine a world where a phone is a wallet with multiple digital denominations that are simply exchanged from phone to phone; what is the transaction limit on that?

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[darkmule]

Do you think there could be a passthrough service for people to send raw transactions (made offline) via postalmail/skype/tor/twitter and then be transmitted on the network? Would be nice for countries that block internet during unrest etc.

Anything that can take a rawtx printed in some standard font (preferably one optimized for OCR) and printed on paper, accept it into a scanner and dump it straight to https://blockchain.info/pushtx would do fine.  An automated system could even feed the paper itself directly into a shredder afterwards.

[threeip]

Is there any security risks in sending a rawtx to a third party, eg exposing addresses etc? Obviously the entire network would see it at some point..

[J35st3r]

Is there any security risks in sending a rawtx to a third party, eg exposing addresses etc? Obviously the entire network would see it at some point..

The only risk is that they don't forward it onto the network. There is nothing in the rawtx that is not already in the blockchain.

[uyjulian]

Good ideas.

[worldtreasurefinders]

How do you transfer Bitcoins without an Internet connection?

Physical bitcoins by Casascius, or any number of paper bitcoin notes you can buy on ebay or create yourself.

[threeip]

Do you think there could be a passthrough service for people to send raw transactions (made offline) via postalmail/skype/tor/twitter and then be transmitted on the network? Would be nice for countries that block internet during unrest etc.

Anything that can take a rawtx printed in some standard font (preferably one optimized for OCR) and printed on paper, accept it into a scanner and dump it straight to https://blockchain.info/pushtx would do fine.  An automated system could even feed the paper itself directly into a shredder afterwards.

Or something ugly like this;

[darkmule]

Worst case, there's always TCP/IP Over Carrier Pigeon as described in RFC-1149.

[malevolent]

- offline or off-chain transactions
- bitcoin private keys secured with one time pads that both parties have chosen beforehand by rolling a dice

[Prophet]

Do you think there could be a passthrough service for people to send raw transactions (made offline) via postalmail/skype/tor/twitter and then be transmitted on the network? Would be nice for countries that block internet during unrest etc.

Anything that can take a rawtx printed in some standard font (preferably one optimized for OCR) and printed on paper, accept it into a scanner and dump it straight to https://blockchain.info/pushtx would do fine.  An automated system could even feed the paper itself directly into a shredder afterwards.

Or something ugly like this;


https://i.imgur.com/6rHMbxL.png

Thousands of them generated by your wallet dynamically and encrypted for immediate distribution face to face, unlockable on receipt of transmission; the dynamic constrution of an off chain mini network. I believe adam back has already devised a method somewhere here on the forum.

[tinus42]

I wonder what the durability of those coins are. Will the tamper-proof stickers last decades not to mention centuries?

[threeip]

I think the problem this is facing, is that you need the unspent outputs from somewhere (ie online) before you can roll a rawtx.
Unless you can just fire off a privkey+outputaddress-esque combo and it just works? 

[ArticMine]

Worst case, there's always TCP/IP Over Carrier Pigeon as described in RFC-1149.

... and under certain circumstances it can be faster than using certain ISPs. For example to transfer the entire blockchain to bootstrap a node.  http://www.news.com.au/technology/pigeon-transfers-data-faster-than-south-africas-telkom/story-e6frfro0-1225771449209

[phillipsjk]

Worst case, there's always TCP/IP Over Carrier Pigeon as described in RFC-1149.

... and under certain circumstances it can be faster than using certain ISPs. For example to transfer the entire blockchain to bootstrap a node.  http://www.news.com.au/technology/pigeon-transfers-data-faster-than-south-africas-telkom/story-e6frfro0-1225771449209

If you read carefully, you will realize that they did not actually implement RFC-1149. RFC-1149 provisions a high latency, low bandwidth llink by printing black stuff on white stuff (paper).

In that story out of South Africa, they made a one-way, high bandwidth, high latency link. If anything, that story shows that RFC-1149 has now been made obsolete by flash memory. I ran the numbers for setting up a service here in Canada to get around high wholesale bandwidth costs: it actually made a stupid amount of sense (being price-competitive). The sticking point was that the Pigeons are a gimmick: since you need to use a courier to transport the Pigeons to their starting point. In that story they also did not appear to include the time required to read and write the memory stick. Most don't write faster than 10MB/s: which would actually be the major bottle-neck.

[darkmule]

I remember when they used to say the highest bandwidth connection was a station wagon full of tapes on the highway.

[nimda]

I remember when they used to say the highest bandwidth connection was a station wagon full of tapes on the highway.

For large amounts of data, SSDs on a plane is still more efficient than the Internet.

[charleshoskinson]

For large amounts of data, SSDs on a plane is still more efficient than the Internet.

I'm sorry but I really couldn't resist:

[CompNsci]

What's wrong with a flash drive with the wallet.dat file on it?

[phillipsjk]

What's wrong with a flash drive with the wallet.dat file on it?

You have to trust that the person who gave you the flash drive will not spend the coins.
You also need an Internet connection to actually check how many coins are actually represented by that wallet.dat

The real answer to the OP is that you really can't securely transfer Bitcoins without an Internet connection, however tenuous. It is one of the weaknesses of the system.

You can use an intermittent connection like dial-up, but you would either have to run a "lite" client, or have the block-chain mailed to you periodically.

[uyjulian]

So... nice ideas! :-)
Thanks!