Title: How to create OFFLINE Transaction? Post by: BTCIndia on November 08, 2014, 07:31:55 AM Private key is converted into public key from one way cryptography thereafter it is used to sign transaction etc etc. Is it possible to create a offline transction?
I mean do all necessary things offline then it would result in some "lengthy random string" which can only be understand and processed by network. Once that lengthy random string is made we can convert into some hash of 32 bytes. Then write it on paper and then decrypt '32 bit hash' with computer connected to internet to yield "lengthy random string" which can be broadcast to network? I don't know much about cryptography. But, I think. It is possible. How can I do it to ensure security of my private key? Title: Re: How to create OFFLINE Transaction? Post by: pooya87 on November 08, 2014, 07:53:06 AM yes in fact there is a way. i don't know about other desktop wallets but in Electrum you can do this easily
take a look at "How to make offline transactions using your Master Public Key" here is the address: https://electrum.org/tutorials.html#offline-mpk Title: Re: How to create OFFLINE Transaction? Post by: franky1 on November 08, 2014, 07:53:50 AM https://en.bitcoin.it/wiki/Raw_Transactions
and https://people.xiph.org/~greg/signdemo.txt will help you in the right direction i would also reccomend learning to do raw transactions on testnet first until you do it right as many peeople have shown to not think about transation fee's or 'change addresses' and ended up having alot of funds send as a fee Title: Re: How to create OFFLINE Transaction? Post by: ruthless09 on November 08, 2014, 08:28:13 AM 1 - convert your private key into your public key and copy your public key onto something that will transfer your public key to an "online computer"
2 - use an online computer to view transactions of the public address/key and to be able to see the unspent inputs of the public key/address 3 - use one of a number of programs/services that can create an unsigned transaction for you 4 - copy the unsigned transaction from step 3 onto a device used in step 1 and copy it back to your offline computer 5 - use your offline computer to sign the transaction in step 4 6 - transfer the now-signed transaction back to your online computer and push it to the network Title: Re: How to create OFFLINE Transaction? Post by: Soros Shorts on November 08, 2014, 08:52:09 AM 1 - convert your private key into your public key and copy your public key onto something that will transfer your public key to an "online computer" 2 - use an online computer to view transactions of the public address/key and to be able to see the unspent inputs of the public key/address 3 - use one of a number of programs/services that can create an unsigned transaction for you 4 - copy the unsigned transaction from step 3 onto a device used in step 1 and copy it back to your offline computer 5 - use your offline computer to sign the transaction in step 4 6 - transfer the now-signed transaction back to your online computer and push it to the network It would be nice if steps 4 and 6 could be done using QR codes and the built-in cameras most mobile computers have. Using other convenient methods such as USB drives might prove to be risky. Title: Re: How to create OFFLINE Transaction? Post by: bluemountain on November 08, 2014, 11:44:00 PM 1 - convert your private key into your public key and copy your public key onto something that will transfer your public key to an "online computer" 2 - use an online computer to view transactions of the public address/key and to be able to see the unspent inputs of the public key/address 3 - use one of a number of programs/services that can create an unsigned transaction for you 4 - copy the unsigned transaction from step 3 onto a device used in step 1 and copy it back to your offline computer 5 - use your offline computer to sign the transaction in step 4 6 - transfer the now-signed transaction back to your online computer and push it to the network It would be nice if steps 4 and 6 could be done using QR codes and the built-in cameras most mobile computers have. Using other convenient methods such as USB drives might prove to be risky. My main concern about this however is that most laptops with digital cameras also come with built in wifi which would potentially make it easy for your "offline" computer to accidentally be an "online" computer Title: Re: How to create OFFLINE Transaction? Post by: Dabs on November 09, 2014, 12:02:29 AM Turn off the wife. I mean, the wifi.
Disable it. Uninstall the driver. No need to physically destroy it, unless you have no other choice. Title: Re: How to create OFFLINE Transaction? Post by: bluemountain on November 09, 2014, 12:08:19 AM Turn off the wife. I mean, the wifi. If you don't physically destroy it then you (assuming you are wearing a tinfoil hat) are risking that the NSA/US government would be able to remotely enable the wifiDisable it. Uninstall the driver. No need to physically destroy it, unless you have no other choice. Title: Re: How to create OFFLINE Transaction? Post by: Spendulus on November 09, 2014, 02:00:01 AM Private key is converted into public key from one way cryptography thereafter it is used to sign transaction etc etc. Is it possible to create a offline transction? First, start with a private key that you are the only one who knows. Test it. I mean do all necessary things offline then it would result in some "lengthy random string" which can only be understand and processed by network. Once that lengthy random string is made we can convert into some hash of 32 bytes. Then write it on paper and then decrypt '32 bit hash' with computer connected to internet to yield "lengthy random string" which can be broadcast to network? I don't know much about cryptography. But, I think. It is possible. How can I do it to ensure security of my private key? Pay zero attention to others who assume that you have a private key and it is secure. Where did it come from? A wallet someone told you to trust? It is not hard to make a private key. Title: Re: How to create OFFLINE Transaction? Post by: BTCIndia on November 09, 2014, 05:39:04 AM Thank you for all the information! I'll try to create offline transaction and if successful will share with community so that other non-technical people can do same.
Title: Re: How to create OFFLINE Transaction? Post by: Dabs on November 09, 2014, 12:49:20 PM If you don't physically destroy it then you (assuming you are wearing a tinfoil hat) are risking that the NSA/US government would be able to remotely enable the wifi Excuse me. I do not wear a tinfoil hat. I wear a chrome-vanadium-tungsten alloy helmet. Aside from protecting against mind reading devices, it also deflects 7.62x51mm NATO ammunition. Also, how would they remotely enable the wifi if it's off and has no drivers installed for it? Title: Re: How to create OFFLINE Transaction? Post by: RobertDJ on November 09, 2014, 07:34:20 PM If you don't physically destroy it then you (assuming you are wearing a tinfoil hat) are risking that the NSA/US government would be able to remotely enable the wifi Excuse me. I do not wear a tinfoil hat. I wear a chrome-vanadium-tungsten alloy helmet. Aside from protecting against mind reading devices, it also deflects 7.62x51mm NATO ammunition. Also, how would they remotely enable the wifi if it's off and has no drivers installed for it? Quote While most of the software is inserted by gaining access to computer networks, the N.S.A. has increasingly made use of a secret technology that enables it to enter and alter data in computers even if they are not connected to the Internet, according to N.S.A. documents, computer experts and American officials. This is not exactly the same as remotely activating the wifi but has similar affects. The technology, which the agency has used since at least 2008, relies on a covert channel of radio waves that can be transmitted from tiny circuit boards and USB cards inserted surreptitiously into the computers. In some cases, they are sent to a briefcase-size relay station that intelligence agencies can set up miles away from the target. The radio frequency technology has helped solve one of the biggest problems facing American intelligence agencies for years: getting into computers that adversaries, and some American partners, have tried to make impervious to spying or cyberattack. In most cases, the radio frequency hardware must be physically inserted by a spy, a manufacturer or an unwitting user. I am not sure how credible their sources are on this story, however if it turns out to be true then the people wearing tinfoil hats may not actually be crazy Title: Re: How to create OFFLINE Transaction? Post by: xrobesx on November 09, 2014, 11:57:01 PM 1 - convert your private key into your public key and copy your public key onto something that will transfer your public key to an "online computer" 2 - use an online computer to view transactions of the public address/key and to be able to see the unspent inputs of the public key/address 3 - use one of a number of programs/services that can create an unsigned transaction for you 4 - copy the unsigned transaction from step 3 onto a device used in step 1 and copy it back to your offline computer 5 - use your offline computer to sign the transaction in step 4 6 - transfer the now-signed transaction back to your online computer and push it to the network It would be nice if steps 4 and 6 could be done using QR codes and the built-in cameras most mobile computers have. Using other convenient methods such as USB drives might prove to be risky. check out the app Bither. There is an app for both Android and iOS. When you first open the app it makes you choose hot or cold wallet. It allows you to use 2 phones, one as cold storage, and sign the transactions with qr codes. Title: Re: How to create OFFLINE Transaction? Post by: coolmyrig on November 10, 2014, 02:14:21 AM it's impossible I think,offline transaction is not easy.
Title: Re: How to create OFFLINE Transaction? Post by: itsAj on November 10, 2014, 03:28:54 AM I never thought there could be an offline transaction because the network has other people that have to confirm the transaction? Interesting information as always from Bitcointalk I never thought this was possible.
Title: Re: How to create OFFLINE Transaction? Post by: Dabs on November 10, 2014, 03:34:18 AM -snip- Quote The technology, which the agency has used since at least 2008, relies on a covert channel of radio waves that can be transmitted from tiny circuit boards and USB cards inserted surreptitiously into the computers. In some cases, they are sent to a briefcase-size relay station that intelligence agencies can set up miles away from the target. -snip--snip- In most cases, the radio frequency hardware must be physically inserted by a spy, a manufacturer or an unwitting user. I am not sure how credible their sources are on this story, however if it turns out to be true then the people wearing tinfoil hats may not actually be crazy Well, then it's a good idea to stuff your offline machine outside the reaches of any radio waves. Underground. Copper mesh cage. Behind 3 meters of steel reinforced concrete. Alternatively, you buy computer parts and assemble it yourself. Anyone who has done any type of bitcoin / alt-coin mining knows how to do this: motherboard, ram, cpu, sata hard drive, etc. The NSA would have to insert the evil hardware into raw computer parts that you would not fail to see unless it was microscopic. Quote The relay station it communicates with, called Nightstand, fits in an oversize briefcase, and the system can attack a computer “from as far away as eight miles under ideal environmental conditions.” Make the environmental conditions not ideal. You wrap your little offline computer in tinfoil, or lead or some other heavy metal, I don't know how anything can get anything from it farther than 8 inches. Title: Re: How to create OFFLINE Transaction? Post by: bluemountain on November 11, 2014, 02:21:26 AM If you don't physically destroy it then you (assuming you are wearing a tinfoil hat) are risking that the NSA/US government would be able to remotely enable the wifi Excuse me. I do not wear a tinfoil hat. I wear a chrome-vanadium-tungsten alloy helmet. Aside from protecting against mind reading devices, it also deflects 7.62x51mm NATO ammunition. Also, how would they remotely enable the wifi if it's off and has no drivers installed for it? Title: Re: How to create OFFLINE Transaction? Post by: Dabs on November 11, 2014, 03:03:23 AM It depends on your use case.
If you are just storing less than a hundred or maybe even a couple thousand bitcoins, then just secure it as best you can where you are. The NSA is not interested in your play money when it costs them more to get it. If you are transacting with tens of thousands or hundreds of thousands of bitcoins, then you better have those 1 foot thick steel walls, little mountains, underground bunkers and other stuff. For everyone in between, a safe or vault will be enough. Real life analogy: I am a private citizen so I carry a single 1911 with 2 extra magazines with me, for daily usage. Only when I'm out on a mission do I carry an M4 with grenade launcher or other tools as needed. I drive an unarmored sedan most of the time. The tank stays at the base. Title: Re: How to create OFFLINE Transaction? Post by: TinaK on November 11, 2014, 07:45:08 AM 1 - convert your private key into your public key and copy your public key onto something that will transfer your public key to an "online computer" 2 - use an online computer to view transactions of the public address/key and to be able to see the unspent inputs of the public key/address 3 - use one of a number of programs/services that can create an unsigned transaction for you 4 - copy the unsigned transaction from step 3 onto a device used in step 1 and copy it back to your offline computer 5 - use your offline computer to sign the transaction in step 4 6 - transfer the now-signed transaction back to your online computer and push it to the network It would be nice if steps 4 and 6 could be done using QR codes and the built-in cameras most mobile computers have. Using other convenient methods such as USB drives might prove to be risky. My main concern about this however is that most laptops with digital cameras also come with built in wifi which would potentially make it easy for your "offline" computer to accidentally be an "online" computer Title: Re: How to create OFFLINE Transaction? Post by: Meuh6879 on November 11, 2014, 02:46:23 PM 1) buy a new laptop (netbook, under the 250 USD)
2) install bitcoin core 3) do transactions 4) don't use this netbook to do others things that's all. price : 1 BTC. Title: Re: How to create OFFLINE Transaction? Post by: Dabs on November 11, 2014, 03:09:56 PM It doesn't even have to be new. You can repurpose an older laptop (erase/wipe, partition, format).
From the savings, buy another router, and connect the bitcoin laptop behind it. Your netbook is now behind at least two routers, and two firewalls. Title: Re: How to create OFFLINE Transaction? Post by: Meuh6879 on November 11, 2014, 05:18:57 PM but it work flawless.
no need to trust 3rd party of a live CD ... for example. and even a USB1.1 port can store the backup of bitcoin core. Title: Re: How to create OFFLINE Transaction? Post by: deluxeCITY on November 11, 2014, 06:10:05 PM 1) buy a new laptop (netbook, under the 250 USD) 2) install bitcoin core 3) do transactions 4) don't use this netbook to do others things that's all. price : 1 BTC. It doesn't even have to be new. You can repurpose an older laptop (erase/wipe, partition, format). From the savings, buy another router, and connect the bitcoin laptop behind it. Your netbook is now behind at least two routers, and two firewalls. but it work flawless. While these are all good suggestions, none would technically create an offline transaction, as they would all be technically online (although the setup would be safer then many setups that many people have). no need to trust 3rd party of a live CD ... for example. and even a USB1.1 port can store the backup of bitcoin core. For the truly paranoid (usually rightfully so as many people have made a lot of money stealing bitcoin from others) you would need to use a computer that has never touched the internet, nor will ever touch the internet in order to generate and store your private keys. Title: Re: How to create OFFLINE Transaction? Post by: BTCIndia on November 17, 2014, 09:00:08 AM Thanks guys for detailed explanation!
Title: Re: How to create OFFLINE Transaction? Post by: coolmyrig on November 18, 2014, 01:20:51 PM I have a idea,how about send it out with a local area network ?
Title: Re: How to create OFFLINE Transaction? Post by: BTCIndia on November 18, 2014, 02:06:08 PM I have a idea,how about send it out with a local area network ? Then its not offline. Title: Re: How to create OFFLINE Transaction? Post by: CIYAM on November 18, 2014, 02:20:29 PM The CIYAM Safe (https://susestudio.com/a/kp8B3G/ciyam-safe) is a Live OS that facilitates performing 100% air-gapped offline tx signing via QR codes.
Title: Re: How to create OFFLINE Transaction? Post by: BTCIndia on November 18, 2014, 02:23:05 PM The CIYAM Safe (https://susestudio.com/a/kp8B3G/ciyam-safe) is a Live OS that facilitates performing 100% air-gapped offline tx signing via QR codes. Thanks! Any youtube link to understand how it do it. Title: Re: How to create OFFLINE Transaction? Post by: CIYAM on November 18, 2014, 02:26:26 PM Thanks! Any youtube link to understand how it do it. Sorry - I am more of a hardcore dev than a youtube video creator. :D At the moment I am also rather busy on other things - but if there is more interest in the CIYAM Safe then I might put some more effort in making it "easier to use" (it works perfectly but does require you to run bash scripts which I understand might be a bit too hard for many potential users). Title: Re: How to create OFFLINE Transaction? Post by: cryptworld on November 18, 2014, 02:45:09 PM you can send a transaction offline,and after that connect to the internet
in that moment,the bitcoins will be sent Title: Re: How to create OFFLINE Transaction? Post by: BTCIndia on November 18, 2014, 02:51:14 PM At http://www.btcguys.us/blog/how-to-create-offline-wallet-with-electrum-bitcoin-client-and-broadcast-transactions, this will help you easily.....Now try it! ::) That's really simple explanation for guy like me. Thanks! It suggests following: Things you will need: 1. two Windows 7 PC, one with internet and one without internet 2. Electrum Bitcoin Client: https://electrum.org/download.html 3. WinMD5Free http://winmd5.com 4. USB 50MB or more Can I use DVD everytime rather than 50MB USB? I don't trust USB anymore. |