Topic: Paper Wallet clients (Read 5328 times)

I was looking for a thermal printer to use with an entropy device. Does anyone have any suggestions?

I am surprised trezor or mycelium doesn't make a thermal printer + entropy device for offline key generation. I know an entropy device can just be connected to an offline printer, but there are so many times where you need a paper wallet, but the ink runs out.

I personally think this would be overly complicated and would be difficult to get the public to use. I disagree with the OP's statement that people want to use technology as little as possible, but rather people generally want to use technology as much as possible. People in the modern world are more then willing to adapt to new technology and generally prefer it.

In regards to it being too complicated, you need to remember that most store clerks make less then 150% of the federal minimum wage and likely do not have a large skill set when it comes to following detailed directions and technology. They also tend to need to have a lot of "fail-safes" that prevent them from making mistakes. I think that this type of system would not be able to be understood by most store clerks and is not very different then using a traditional phone wallet, only that paper is used instead of your phone.

Easiest way is to download either Mycelium (my favorite!) or Hive apps on your phone. They both have a cold storage spending option. You can also in Port the private key in your Blockchain.info wallet as well.

Yes, you right, but how will it affect on btc geek community??? But, in my opinion, it would be nice. Good idea!

The concept would have two main applications. Allowing offline transactions (mainly 3rd world countries) and raising awareness and utility for the bitcoin ecosystem by allowing integration to the current model by reducing the need for consensual change. Therefore I see no problem walking into a gas station, buying a bottle of coke with a 1MS bill, and getting a few pennies or zimbabe back.

I don't think there is a legal issue, it may be defines as a exchange service since you can buy bit coins for dollars, but they r just gonna have to deal with that we will abide by regulations. I have studied the cases of e gold and the liberty dollar and this is different shutting us done would be much more difficult

Bitcoin paper is exactly like Monopoly money. The only difference is there are more people willing to trade stuff for it. You don't see anyone shutting down Parker Brothers.

I agree, but after reading about Liberty Dollar I don't want to be first in line to start the printing.

Unless you are buying exactly the amount of the pre-denominated bills, where will your change go?

I think its time we actually print currency for mass adoption. I was thinking that in order to make this feasible (ATM i don't have a billion dollars) we would only charge the bill with bit coins after payment is received. they would be distributed from a series of authorized vendors e.g. CVS. the customer would walk in to CVS and Purchase pre-denominated bills at the sum of 10KS, 100KS, 1MS,10MS & 1BTC (thousand satoshi and million satoshi respectively). When the teller scans the bills for check out they will be activated, at time of activation BTC will be sent  to the bills (which now become paper wallets). The Bills will have watermarks and different colors for different denominations. This business model will make revenue from charging a 10% premium for the service. If anyone is interested please reply or PM me:)

Paper based bitcoins really can only be used between trusted parties. In practice it seems to be heavily used to sell and give bitcoins to people that aren't set up yet to receive bitcoins. It makes for an excellent transitional medium (people are used to paper money).

Some just keep with paper (treating it as a long term investment), and some become part of the bitcoin economy. In either case it a valuable tool to introduce new users.

That said, if you walked up to me and I didn't know you enough to trust you and you were trying to buy something off of me with paper bitcoins, I would probably just import them directly before considering them mine. Of course, the amount of bitcoins in question makes a big difference. If it is less than $10 worth, I might just pocket it and call it good enough for now.

I'm wondering if this layout can't be changed a little so that a 3-of-3 transaction is made to send the original load to check 001 that requires a private key card to authorize the final transfer to it. The store owner then sweeps the private key from check 001 and sends the change to check 002 with another 3-of-3 transaction using the customer's key card public address. I'm not certain if this use of a combined sweep and m-of-n script is possible. Maybe this is actually conducting too many transactions in too short of a window.

Oh, now I get what you are describing.   This would allow a person to redeem a paper bitcoin at a merchant, for example, without having the exact amount.  Here's how I now understand it to work: The paper bitcoin is presented to the merchant.  The merchant scans both the private key and the "to here" address.  The merchant then creates a transaction which has the first output going to the merchant's Bitcoin address for the amount of the purchase, and then the second output goes to the "to here" address.

Of course this puts a delay between when you can use the first paper wallet and the second one.  One confirmation (about ten minutes) is all that is needed though before spending the second one.

There is the risk that the merchant doesn't actually send the change transaction and the customer with the paper wallet wouldn't know that happened until attempting to spend the second paper wallet.  But if the merchant provides a printed receipt with the details of the transaction at the time of the sale then the customer would have all the information needed to resolve any dispute if the funds don't arrive.

There is also the risk that the merchant scans the private key but cannot (or does not) process the transaction.  Should that happen, there is the risk that before the customer is able to use that private key elsewhere (e.g., upon return home) the merchant then fraudulently spends the coins.  There's almost no way for the customer to prove the merchant had spent them.  But maybe the merchant really didn't spend them -- maybe the customer spent them upon return home with the intention of accusing the merchant of having spent them (in an attempt to get the merchant to pay a refund).  This just opens an opportunity for one party to scam the other in which there is a fairly decent chance of being successful with a fairly low chance of getting caught as there's almost no way to prove who really spent the funds.

Now instead if this is a way for two parties which trust each other to transact where one party wishes to use a paper wallet system, these would work wonderfully.

p.s. one caveat on the design -- the actual keys should be printed out in case of the need for manual entry (e.g., no QR scanner available or the scanner used couldn't detect the code.)

Yes, that is exactly my point. This will still require a Bitcoin Network transaction, but let the vendor worry about the geeky stuff. No matter how secure you make Bitcoin, it will be possible to scam some people with anything you design.

then let them use paper money. using bitcoin like this is like sending tcp ip packets per mail because you like the internet but its just "too online".

Here's just a basic concept of a bitcoin checkbook. Different layouts can be used to add security. Also, a key card, sms phone, etc. could be used for multisig requirements.

There are reasons for paper transfer of bitcoin value but whenever real-world scenarios are described, the fraud potential between when the paper is issued (e.g. spit out of a receipt printer) and when it gets redeemed (scanned for redemption a few hours later) is too great.  It is only a matter of time before the flaws are exploited and users lose coins.

If you are wanting a paper wallet to hold bitcoins securely yourself until redemption days, months or years later, then perhaps some specialized device that you could own would someday be created that would provide that.  Something perhaps like the Raspberry Pi Offline Paper Wallet Creator discussed here:
- https://bitcointalksearch.org/topic/offline-paper-wallet-creator-raspberry-pi-74615

Here's another thread describing the problems in accepting a paper wallet from a third party:
 - https://bitcointalksearch.org/topic/m.810361

It really boils down to that the wallet needs to be redeemed soon enough after issue such that neither side has an opportunity to defraud the other without detection.  The only exception is for the physical bitcoin products which are secured with a hologram or other such protection.  So far though, those physical coin and paper wallet methods cost about $2 per blank.

There was discussion of a "half wallet" approach here:
 - https://bitcointalksearch.org/topic/new-conceptideaproduct-secure-bitcoin-wallet-seeds-56414

As far as a client specifically for loading, sweeping and verifiying paper bitcoins (QR code or manual entry (copy/paste) of the keys) that is already solved for the most part, using services that exist already (e.g., Mt. Gox does load and sweep, My Wallet from http://BlockChain.info/wallet does most of that as well, and I believe one or more of the other clients (Armory?) are on the job for this too).

A dead-simple standalone app and/or site just for this purpose could be built without much difficulty if there was demand.

[Update: Not sure how this fits in but wanted to share it:]
 Flexible, plastic electronic displays -- digital paper:
 - http://www.gadgetguy.com.au/lg-makes-digital-paper-a-reality-could-change-newspapers-and-clothing

Many find paper money comforting and don't trust themselves using technology any more than necessary. I would like to see a paper mode for clients or even stand alone clients that don't display addresses. It won't be used for sending money to remote addresses over the internet, but instead will be used to print, load, sweep, and verify paper bit bills. Standard computer printers could print out a stack to be used like a checkbook. They could be designed to require a key card as well or any other multisignature security device. The top check will have a load and when swept, the value will go to the paper bill below in the series printed. I just see this as a way to remove the geek factor from Bitcoin for the masses.

It would be interesting to come up with a nice template for the notes. They could be printed in bulk without the actual codes in color and sold in stores. It would then just be a matter of printing out a checkbook full of sweepable bills.