Would it be possible to sign transactions offline and email them?

Dabs

legendary

Activity: 3416

Merit: 1912

The Concierge of Crypto

Quote from: foggyb on March 24, 2013, 11:34:37 PM

Interesting. This means transactions through postal mail could work as well?

Yes, but it will have to pass through either an automatic OCR or some human is going to have to process it. An anonymous email to broadcast transaction portal would be better. Something like a anon remailer that uses OpenPGP or something, with included optional time delay. Then you could use a couple of anon remailers chained in sequence to transmit the transaction almost completely offline, anonymously, and very difficult or impossible to trace.

Postal mail would have to go through a person.

foggyb

legendary

Activity: 1708

Merit: 1006

Interesting. This means transactions through postal mail could work as well?

remotemass

legendary

Activity: 1122

Merit: 1017

ASMR El Salvador

Quote from: Gabi on February 28, 2013, 01:45:07 PM

Anyway, you can for example copy-paste the transaction somewhere on the blockchain.info site and it will relay it to the bitcoin network. Sorry, i can't find the exact link of that feature right now.

The link you are mentioning must be, http://blockchain.info/pushtx, that is mentioned on pg. 60 of Bitcoin Magazine, issue #4 November 2012.

Elwar

legendary

Activity: 3598

Merit: 2386

Viva Ut Vivas

Quote from: Timo Y on March 01, 2013, 04:22:47 AM

Quote from: Elwar on February 28, 2013, 05:01:01 PM

I could see this for people at work wanting to send come BTC. My work filter blocks about 80% of Bitcoin sites including blockchain.org. And I cannot install anything on my PC without going through my sys admin.

Probably much easier just to send bitcoins from your private smartphone. Or are workplaces jamming phones now too?

No phones allowed...but going down a rabbit hole of how I could send Bitcoins at my work would be useless with the restrictions. If I really have to send BTC while at work I can go outside and send it via smartphone.

I am supposed to only be doing work at work anyway, which I always follow Wink

auzaar

full member

Activity: 151

Merit: 100

If you can generate txn offline, which you can do, emailing part is trivial

create a google app engine app, set incoming emails
https://developers.google.com/appengine/docs/python/mail/receivingmail

on email post it to https://blockchain.info/pushtx

I will do it for 5 btc

Timo Y

legendary

Activity: 938

Merit: 1001

bitcoin - the aerogel of money

Quote from: Elwar on February 28, 2013, 05:01:01 PM

I could see this for people at work wanting to send come BTC. My work filter blocks about 80% of Bitcoin sites including blockchain.org. And I cannot install anything on my PC without going through my sys admin.

Many workplaces also prohibit inserting unapproved USB drives into your work computer because they are afraid of malware and data theft.

In that case, your only option is to generate the signature on your portable device and type it into your work computer by hand.

Probably much easier just to send bitcoins from your private smartphone. Or are workplaces jamming phones now too?

picobit

hero member

Activity: 547

Merit: 500

Decor in numeris

The Armory client has support for offline wallets, where you can create a transaction on computer A which has the blockchain and your public keys, but not your private keys. Then you transfer the unsigned transaction to computer B, which is typically offline and thus secure from hackers, and has your private keys. You sign the transaction, and transport it to computer C which is online, and broadcast the transactions. Typically computer A and C are the same, but not necessarily.

remotemass

legendary

Activity: 1122

Merit: 1017

ASMR El Salvador

Quote from: Elwar on February 28, 2013, 05:01:01 PM

(...) And I cannot install anything on my PC without going through my sys admin.

Maybe a 'portable app' for Satoshi client will come about, that you can use from your pendrive.

Stephen Gornick

legendary

Activity: 2506

Merit: 1010

Quote from: remotemass on February 28, 2013, 01:41:18 PM

I'm thinking in terms of being possible to do transactions if you only had access to email.

You can, but for the inputs on that transaction it needs to know the transaction hashes (and indexes) that are being spent. This comes from the blockchain. It doesn't have to be a live or even recent copy of the blockchain, as long as it was as as-of when all transactions received and now being spent had at least one confirmation (and have not been spent since).

- http://en.bitcoin.it/wiki/Raw_Transactions

So even an offline computer with a copy of the blockchain and a wallet.dat can be used to compose the raw transaction. That raw transaction can then be transported (via e-mail attachment, flash drive/sneakernet, or whatever communication method you want, and broadcast. It can be broadcast by any Bitcoin.org client node (sendrawtransaction API method), or using services:

- https://blockchain.info/pushtx
- http://brainwallet.org/#tx

Elwar

legendary

Activity: 3598

Merit: 2386

Viva Ut Vivas

I could see this for people at work wanting to send come BTC. My work filter blocks about 80% of Bitcoin sites including blockchain.org. And I cannot install anything on my PC without going through my sys admin.

nevafuse

sr. member

Activity: 247

Merit: 250

Quote from: remotemass on February 28, 2013, 01:52:40 PM

In case your ISP, in a dystopian future, blocked you from using p2p software and you didn't want to use an online wallet.

By that time, wifi will be good enough to form an ad hoc network

remotemass

legendary

Activity: 1122

Merit: 1017

ASMR El Salvador

In case your ISP, in a dystopian future, blocked you from using p2p software and you didn't want to use an online wallet.

Gabi

legendary

Activity: 1148

Merit: 1008

If you want to walk on water, get out of the boat

Yes.

But why the email? Sending a transaction to the bitcoin network doesn't compromise your private key. If you are so paranoid, just do the transaction on a offline pc, copy it on an online pc and send it from there, why the email?

Anyway, you can for example copy-paste the transaction somewhere on the blockchain.info site and it will relay it to the bitcoin network. Sorry, i can't find the exact link of that feature right now.

remotemass

legendary

Activity: 1122

Merit: 1017

ASMR El Salvador

I'm thinking in terms of being possible to do transactions if you only had access to email.
Is it foreseeable that a bitcoin email technology will arise that will allow us to send money from one bitcoin address - using only email - without compromising the private key?

Topic: Would it be possible to sign transactions offline and email them? (Read 1187 times)