## Removing Bitcoin from my phone to secure storage

1

I am using the following Bitcoin wallet for Android:

https://github.com/bitcoin-wallet/bitcoin-wallet

My device is encrypted and I have encrypted backup files on Google Drive.

However, I'd like to get my coins off my phone altogether, just in case its stolen and the UI is still accessible. I'd like to keep a small amount on my phone, and top up that balance every now and then.

What's the best way to do this?

I think I need a separate "long term" wallet, but that's just moving the same problem to somewhere else.

Is a hardware wallet the only way to go here?

1

You are overthinking this. The easiest way to move some of your bitcoin to a different wallet is simply to send it to an address belonging to the second wallet. This works, regardless of what type of wallet the second wallet is.

For example, if you use Bitcoin Core on a desktop in your house, simply request a payment, which will show a QR code on your screen. Scan it with your phone, and send whatever amount of bitcoin you want to your desktop wallet. Yes, there will be a transaction fee, but it will be a lot less value than the time/risk associated with importing private keys into Bitcoin Core and then purging them from your phone wallet.

As for the most secure wallet for long term storage...there's some debate on that. Here's an earlier answer I gave on the subject: What options does one have to manage Bitcoins?

Seems sensible. I have since invested in the Ledger Nano Pen "Drive". I'll use this with my Desktop where I'll keep the bulk of my coin, and send to my Phone as required. – Garreth McDaid – 2017-01-04T09:13:31.993

0

Not necessarily. If you have a computer which you trust to be secure when you store your large amount of money for the long term and one you trust to be secure when you retrieve your money or part of it (not necessarily the same computer, and even if it's the same computer, it can be a malware-infested mess in the time in-between) and an encryption method you trust to be secure, you can store your data digitally.

Storing it digitally makes it easy to distribute it: You can store it on every internal hard drive, on your phone(s), on your external hard drives, on your thumb drives, at cloud services, you might even cramp out a CD and burn it to it. Of course, only do this with an encrypted wallet.

One super easy way to do this is to create a text file containing the private key inside an encrypted 7zip file. I don't exactly like the 7zip format but you got to admit software able to read it is pretty wide-spread, making it very likely that you'll easily find a machine which can read and decrypt it, even in the far future. Plain text will always be readable, so that's safe to be retrievable, too.

## Yeah, yeah, but I can't print an encrypted 7zip file. I want my long-term stuff to be on paper!

Bitcoin private keys in wallet import format are 52 Byte long. Depending on the text editor you use, that means the file will be either 52 or 53 Byte on a Linux or Mac system or 52 or 54 Byte on a Windows system. In any case, just choose a 1 character file name and you should end up with an encrypted 7zip file of about 230 Byte. Print that out in hex, it fits easily onto a single page. The example file I just produced is in hex:

37 7A BC AF 27 1C 00 03 3B 7A 70 60 A0 00 00 00 00 00 00 00 26 00 00 00 00 00
00 00 40 8A 40 97 19 9A F8 A6 16 69 27 09 DA 6C A3 79 F1 FD 28 6D 76 9F 45 40
9D FE D1 9A 89 AC 36 55 8C DF B2 22 C2 EB 36 12 4D B6 9D 17 76 D6 BC 4E 8B A3
DC 68 8B 0D 50 08 F8 76 17 8C B2 DF 56 E8 D5 AC 17 48 2B 11 52 1F 20 94 83 0F
02 BA 48 D1 07 BF E7 1E 22 9F AC 6D 43 97 ED 8E 37 36 E6 63 2B 3E 12 0E 53 7A
2F D8 64 10 2D AF AD DB 25 98 60 16 B1 09 29 22 E0 1B 90 31 17 26 66 3E EB 29
99 87 1C A4 2D 3F 38 20 C6 81 D0 2D DF 14 8D 2B 52 1B FE D7 2D D5 1C FE 0E 4A
73 DC 53 F2 4E 89 58 E3 B8 82 17 06 40 01 09 60 00 07 0B 01 00 01 24 06 F1 07
01 0A 53 07 07 21 88 AD 58 CD E8 B8 0C 55 0A 01 BC D2 3F 41 00 00


I would print a bit more, though:

2017-01-03  Bitcoin Paper Wallet by Garreth McDaid
Amount:     1.4 BTC
File Type:  Encrypted 7zip Archive
Sha256sum:  6daca655579085097e7289cc1979156de7a8868f1f058ec2dd8b3db2f59b5695

37 7A BC AF 27 1C 00 03 3B 7A 70 60 A0 00 00 00 00 00 00 00 26 00 00 00 00 00
00 00 40 8A 40 97 19 9A F8 A6 16 69 27 09 DA 6C A3 79 F1 FD 28 6D 76 9F 45 40
9D FE D1 9A 89 AC 36 55 8C DF B2 22 C2 EB 36 12 4D B6 9D 17 76 D6 BC 4E 8B A3
DC 68 8B 0D 50 08 F8 76 17 8C B2 DF 56 E8 D5 AC 17 48 2B 11 52 1F 20 94 83 0F
02 BA 48 D1 07 BF E7 1E 22 9F AC 6D 43 97 ED 8E 37 36 E6 63 2B 3E 12 0E 53 7A
2F D8 64 10 2D AF AD DB 25 98 60 16 B1 09 29 22 E0 1B 90 31 17 26 66 3E EB 29
99 87 1C A4 2D 3F 38 20 C6 81 D0 2D DF 14 8D 2B 52 1B FE D7 2D D5 1C FE 0E 4A
73 DC 53 F2 4E 89 58 E3 B8 82 17 06 40 01 09 60 00 07 0B 01 00 01 24 06 F1 07
01 0A 53 07 07 21 88 AD 58 CD E8 B8 0C 55 0A 01 BC D2 3F 41 00 00

37 7A BC AF 27 1C 00 03 3B 7A 70 60 A0 00 00 00 00 00 00 00 26 00 00 00 00 00
00 00 40 8A 40 97 19 9A F8 A6 16 69 27 09 DA 6C A3 79 F1 FD 28 6D 76 9F 45 40
9D FE D1 9A 89 AC 36 55 8C DF B2 22 C2 EB 36 12 4D B6 9D 17 76 D6 BC 4E 8B A3
DC 68 8B 0D 50 08 F8 76 17 8C B2 DF 56 E8 D5 AC 17 48 2B 11 52 1F 20 94 83 0F
02 BA 48 D1 07 BF E7 1E 22 9F AC 6D 43 97 ED 8E 37 36 E6 63 2B 3E 12 0E 53 7A
2F D8 64 10 2D AF AD DB 25 98 60 16 B1 09 29 22 E0 1B 90 31 17 26 66 3E EB 29
99 87 1C A4 2D 3F 38 20 C6 81 D0 2D DF 14 8D 2B 52 1B FE D7 2D D5 1C FE 0E 4A
73 DC 53 F2 4E 89 58 E3 B8 82 17 06 40 01 09 60 00 07 0B 01 00 01 24 06 F1 07
01 0A 53 07 07 21 88 AD 58 CD E8 B8 0C 55 0A 01 BC D2 3F 41 00 00

2017-01-03  Bitcoin Paper Wallet by Garreth McDaid
Amount:     1.4 BTC
File Type:  Encrypted 7zip Archive
Sha256sum:  6daca655579085097e7289cc1979156de7a8868f1f058ec2dd8b3db2f59b5695

37 7A BC AF 27 1C 00 03 3B 7A 70 60 A0 00 00 00 00 00 00 00 26 00 00 00 00 00
00 00 40 8A 40 97 19 9A F8 A6 16 69 27 09 DA 6C A3 79 F1 FD 28 6D 76 9F 45 40
9D FE D1 9A 89 AC 36 55 8C DF B2 22 C2 EB 36 12 4D B6 9D 17 76 D6 BC 4E 8B A3
DC 68 8B 0D 50 08 F8 76 17 8C B2 DF 56 E8 D5 AC 17 48 2B 11 52 1F 20 94 83 0F
02 BA 48 D1 07 BF E7 1E 22 9F AC 6D 43 97 ED 8E 37 36 E6 63 2B 3E 12 0E 53 7A
2F D8 64 10 2D AF AD DB 25 98 60 16 B1 09 29 22 E0 1B 90 31 17 26 66 3E EB 29
99 87 1C A4 2D 3F 38 20 C6 81 D0 2D DF 14 8D 2B 52 1B FE D7 2D D5 1C FE 0E 4A
73 DC 53 F2 4E 89 58 E3 B8 82 17 06 40 01 09 60 00 07 0B 01 00 01 24 06 F1 07
01 0A 53 07 07 21 88 AD 58 CD E8 B8 0C 55 0A 01 BC D2 3F 41 00 00

37 7A BC AF 27 1C 00 03 3B 7A 70 60 A0 00 00 00 00 00 00 00 26 00 00 00 00 00
00 00 40 8A 40 97 19 9A F8 A6 16 69 27 09 DA 6C A3 79 F1 FD 28 6D 76 9F 45 40
9D FE D1 9A 89 AC 36 55 8C DF B2 22 C2 EB 36 12 4D B6 9D 17 76 D6 BC 4E 8B A3
DC 68 8B 0D 50 08 F8 76 17 8C B2 DF 56 E8 D5 AC 17 48 2B 11 52 1F 20 94 83 0F
02 BA 48 D1 07 BF E7 1E 22 9F AC 6D 43 97 ED 8E 37 36 E6 63 2B 3E 12 0E 53 7A
2F D8 64 10 2D AF AD DB 25 98 60 16 B1 09 29 22 E0 1B 90 31 17 26 66 3E EB 29
99 87 1C A4 2D 3F 38 20 C6 81 D0 2D DF 14 8D 2B 52 1B FE D7 2D D5 1C FE 0E 4A
73 DC 53 F2 4E 89 58 E3 B8 82 17 06 40 01 09 60 00 07 0B 01 00 01 24 06 F1 07
01 0A 53 07 07 21 88 AD 58 CD E8 B8 0C 55 0A 01 BC D2 3F 41 00 00


The checksum is to verify whether the data is correct. If you use OCR software, it might get something wrong. If you have to type it in by hand, you might get something wrong. And you probably want to be able to find out whether [the file you created is wrong because you put a typo in or your hex editor isn't working properly] or [the archive software on that computer which isn't reading encrypted 7zip archives correctly]. Redundancy is good, in this case, and it still fits on a single page.

Sending this to a public printer is perfectly safe. In fact, you can hide these sheets of paper even in placed where other people can find them. If your password is strong enough, they won't be able to access your money.

Just whatever you do: Don't use a brain wallet! And don't repeat the same mistakes people using brain wallet make: Don't use common phrases or lyrics of songs you like as passwords.

This looks like it was meant to be an edit of your first answer, not a second one. Thought you should know :) – Jestin – 2017-01-03T22:35:02.360

@Jestin Yeah, noticed this before you submitted the comment and already deleted the other answer. I have no idea how that became a second answer but thanks for hinting that to me. – UTF-8 – 2017-01-03T22:36:13.827