using old phones as cold wallets

[eclecticuniversalas]

Im new at this and have only been studying bitcoin for 5 days, . .I already have linux running off usb and harddrive so this fits naturally with the tranfer to an offline cold wallet idea, so my question is, I have all these old verizon and samsung phones lying around, , would it be possible to reburn the internal structure erasing all data and severing all connections thru bluetooth internet, phone etc. . . where it simply becomes an offline wallet that gernerates address keys in the form of qr codes and you can go through your offline password protected wallet, . . gereate a qr and the show it to someone elses phone etc. . . its an airgap for you personal finances that you control, . and could old phones then be recycled into cold storage wallets

[1714806665]

1714806665

[gsxrboy]

why not paper wallet , if you want to go through all that trouble, electronic components can fail over time.

[eclecticuniversalas]

because i can then replicate and easily make bob an offline secure wallet on the fly so he caan use bitcoin, I can walk down the street and make an easy transaction , . . and yes electronics can fail, thats why you make a backup, . .but a single qr screen personal transaction wheteher across the table or across the ocean via phone is faster without the paper trail, . I thought it also might help the system go mainstream and secure in an easy way my friend bob could get online, . .besides , I want one for myself, perferably linux open source simple on off wallet where i control my funds. im holding an old sprint htc in my hands right now thinking, what if i downloaded a simple program on this and made it my wallet, . . where when i trade with you or online, i simply reveal a single screen qr code to you, . when the transaction is complete, i turn it off, . . if i want to put funds online , .  i simply take my phone and take a picture of my wallets qr code i show it and it transfers those funds and only those funds to my online funds.. . . if its an easy portable wallet with a very basic simple interface designed to do only one thing, . bitcoin would become more easily available and easier to use for the masses, ...

[Kemarit]

You may want to check this thread:

https://bitcointalk.org/index.php?topic=210261.0

This is a similar concept as yours and has been discussed before.

Anyways, Goodluck to your project!!!

[eclecticuniversalas]

thank you for that link, . its from 2014 but a lot of good info, for one its been done, so two it should be tweakable on open source to suit my needs, . generally all i want is an ( offline qr generator and personal account ledgers program on a small portable wallet) which i can backup through the existing usb/power charging cord while remaining completely off grid) which i can then display on screen a qr and scan it with my real phone to put it online and transfer, then shut the wallet of and go, . i could also scan the funds onto a second formatted phone empty offline wallet  and take that around to the coffee shop for quick personal transactions via a qr i just loaded for hat transaction, . yes its dangerous to have all your funds on a phone or two or paper and yes you have to protect the physical funds yourself, . but thats what it is with a bank free currency, . . also a free rom flash program for dead phones allows me to build wallets which will work with any other already existing qr systems such as coinbase, mycellium, etc. . (my real phone scans my wallets onscreen qr this working through qr  makes it easily cross platform, . it simple, its basic, and once the first flash rom program is written i can make offline wallet after wallet in quantities by flashing rom (or whatever they do to phones) , one of my concerns about bitcoin has been in a time of fiat imbalance and collapse, if you want the masses to be able to transfer to a safe secure system, they need to learn how to put a linux iso on a usb and then learn to swap usb and manage transfers, . where if the guy down the street can flash offline wallets for $5 it makes it easier for people who are used to phones already , . even now i could in theory flash phones immediately capable of transferring from any online exchange into a wallet from the second you turn it on, . .i can then give out these cold wallets to friends and each one could have a permanent printed donation public key qr on the back for donations, . i can then pass out these wallets which work straight out of the box,  with instructions on backing up data vs usb or offline printer and include that in its software as a function, . . am i missing something here as i am new to btc, . and thanks again for that link, . i will probably start looking for help in the open source linux and android programmers as welll, . . it simply writing a (linux iso type usb bitaddress offline qr generator) onto a phone and adding a simple account managing software, . It can have an opening pattern lock like a phone when you turn it on, and be encrypted and password protected as well, .  its so small any old phone from any era should carry more than enough memory and processing power for it, . to me it would seem to help the ease of use problem as it would work straight out of the box and work cross platform online as well.  . anyway, thanks and i will chase this down further in other areas, . I quess my only real question is , . Is there something I am missing that makes this undoable in btc or any logical non biased reason it will not work as i imagine it, . .thank you for your help and time

[manselr]

why not paper wallet , if you want to go through all that trouble, electronic components can fail over time.

Paper wallets can get lost unless you make tons of copies. They can (and will) deteriorate with time too, you can make it last a lot if you wrap it on plastic tho, but I think paper long term will deteriorate even if sealed on plastic and you don't want to end up with a QR code that doesn't properly scan, so I think several copies on several platforms are the best. Paper and digital, and an old phone is not a bad idea. I think old simple phones break harder than the new more complex ones that overheat often.

[Raimonn]

Would be nice, to have a new use for old phones as a hardware wallet. Phones have camera to scan QR and can show QR. I was worried about how much can last an old device, but you are right, we always can have a backup of the wallet stored at home.

[Decoded]

Would be nice, to have a new use for old phones as a hardware wallet. Phones have camera to scan QR and can show QR. I was worried about how much can last an old device, but you are right, we always can have a backup of the wallet stored at home.

Why not use the backup ad your cold storage? Because a phone is very susceptible to damage, and most phones use low quality flash storage, like the ones in USBs, not like SSDs. They're not built to retain information for more than a couple of years.

[BigBoom3599]

I've done this myself and it worked quite well. I used Bither for this, it's quite easy actually. I just completely wiped the phone, turned off all wifi/mobile data (took out the sim), installed Bither's apk and then I could generate a wallet. If you want to send a transaction you generate it on your phone (not the cold storage one) in the bither app, then you send it to the cold phone via qr and then you can scan the signed tx and broadcast it. I really liked it, but I stopped using it because it doesn't support altcoins.

[U2]

Phones = computers so cold storage can be set up pretty much the same as doing this on a computer. It's a good idea too because if your house got robbed who the hell is going to steal your old piece of crap phone? Lol. The only issue I can think of is the OS but you should probably be able to flash Linux on them I'm assuming.

[miningdude]

It's good idea, as phones you can't lost the date of the cold wallet, but it takes time to send btc

[shield132]

why not paper wallet , if you want to go through all that trouble, electronic components can fail over time.

Paper wallets can get lost unless you make tons of copies. They can (and will) deteriorate with time too, you can make it last a lot if you wrap it on plastic tho, but I think paper long term will deteriorate even if sealed on plastic and you don't want to end up with a QR code that doesn't properly scan, so I think several copies on several platforms are the best. Paper and digital, and an old phone is not a bad idea. I think old simple phones break harder than the new more complex ones that overheat often.

Why such opinion about paper wallet? Everything can be lost and phone isn't exception. I agree to gsxrboy, we can print some paper wallet and than save them on secure area so we will avoid trouble of electronic and also paper isn't damaging as you explain. Imagine old books which lasted centuries without damage and if we will wrap it on  plastic it feels more secure.

[User365]

why not paper wallet , if you want to go through all that trouble, electronic components can fail over time.

Paper wallets can get lost unless you make tons of copies. They can (and will) deteriorate with time too, you can make it last a lot if you wrap it on plastic tho, but I think paper long term will deteriorate even if sealed on plastic and you don't want to end up with a QR code that doesn't properly scan, so I think several copies on several platforms are the best. Paper and digital, and an old phone is not a bad idea. I think old simple phones break harder than the new more complex ones that overheat often.

Why such opinion about paper wallet? Everything can be lost and phone isn't exception. I agree to gsxrboy, we can print some paper wallet and than save them on secure area so we will avoid trouble of electronic and also paper isn't damaging as you explain. Imagine old books which lasted centuries without damage and if we will wrap it on  plastic it feels more secure.

If you store a big amount of money you could buy a small piece of metal and engrave the code

[OgNasty]

If you store a big amount of money you could buy a small piece of metal and engrave the code

Physical wallets utilizing this method are another option, although they require 3rd party trust.

https://nastyfans.org/mint

[HarringtonStark]

why not paper wallet , if you want to go through all that trouble, electronic components can fail over time.

Yeah and keep them locked in a safe. That's what I will do next. I too don't throw away my previous phones and they are from good brands so they're very unlikely to fail easily because of quality