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Topic: Easy cold storage with Tails Linux, and Electrum for newbies (Read 687 times)

legendary
Activity: 2898
Merit: 1823
Bitkey is ok, but it has not been updated since since 2017, or early 2018. For purposes of cold storage, I would still choose Tails, and follow as instructed in the OP.

The people maintaining Tails are very active in patching the OS for bugs and from security exploits.
newbie
Activity: 5
Merit: 0
The Electrum wallet in Tails are outdated, so some exploit might be used to capture your seed. It is also not recommended to create the persistent volume, if you are prompted to do that.

Some early malware like BADUsb hides in the firmware of the USB drives, so it can be adapted to capture private keys and your Seed, if they wanted to. If you re-use the USB before you destroy it, then your Seed will be compromised.

These days you can buy a old second hand computer for the price of a USB drive, so I would much rather buy a old computer and printer and print a bunch of paper wallets and destroy that.  Wink  

Good point. For this purpose there's really no need for a persistent volume.
About the rest, this is way above my level of paranoidity.

I'm still happy with my ledger nanos. Of course eventually every hardware wallet can get hacked - as seen on wallet.fail - but you would need physical access. To get motivated to break into my house one would first need to know that I even have bitcoins.

I think the short howto is really good.

Speaking about alternatives for Tails, has anyone used the distro bitkey? I've been using that quite a lot lately and its really convenient.
https://bitkey.io/

But I'm not completely sure this is safe, too. Could theoretically include a malicious electrum version, too.
legendary
Activity: 2898
Merit: 1823
The Electrum wallet in Tails are outdated, so some exploit might be used to capture your seed. It is also not recommended to create the persistent volume, if you are prompted to do that.

Some early malware like BADUsb hides in the firmware of the USB drives, so it can be adapted to capture private keys and your Seed, if they wanted to. If you re-use the USB before you destroy it, then your Seed will be compromised.

These days you can buy a old second hand computer for the price of a USB drive, so I would much rather buy a old computer and printer and print a bunch of paper wallets and destroy that.  Wink 


But if we are talking about that level of paranoia, then everything can be hacked, and stolen from you. Hardware wallets, your smart phones, your computers, the software, the operating systems, Bitcoin, everything.
legendary
Activity: 3542
Merit: 1965
Leading Crypto Sports Betting & Casino Platform
The Electrum wallet in Tails are outdated, so some exploit might be used to capture your seed. It is also not recommended to create the persistent volume, if you are prompted to do that.

Some early malware like BADUsb hides in the firmware of the USB drives, so it can be adapted to capture private keys and your Seed, if they wanted to. If you re-use the USB before you destroy it, then your Seed will be compromised.

These days you can buy a old second hand computer for the price of a USB drive, so I would much rather buy a old computer and printer and print a bunch of paper wallets and destroy that.  Wink 
legendary
Activity: 1666
Merit: 1196
STOP SNITCHIN'
You can't really compare the bug that was found in Core, which was theoretical at best, and fixed anyway before it even had a chance to do anything.

The Electrum bug as explained by theymos sounded as if you were just a click away from losing your coins:

Quote from: theymos
This message is false, sent to you by a hacker. If you click the link in the message and install the software, then your BTC will be stolen.

When has Bitcoin Core had anything like that?

I wouldn't compare the two either, but the recent bug in Core was far more serious. It was "theoretical" in the sense that all bugs that haven't been exploited yet are theoretical. Since you quoted theymos:

The bug fixed in Bitcoin Core 0.16.3 was really bad. IMO it was the worst bug since 2010. If it had been exploited in a 0-day fashion, significant & widespread losses (due to acceptance of counterfeit BTC) would've been likely, and Bitcoin's reputation would've long been tarnished. Furthermore, since a ton of altcoins are based on Bitcoin Core, this would've affected a huge swath of the crypto space all at once.

I encountered the Electrum attack. To be honest, it wasn't very convincing. It was a social engineering attack, not an actual vulnerability in the software. You would have had to open an external untrusted website, download the software, and also neglect to verify it. Plus, the malware only worked if you kept your Electrum keys online, which isn't necessary.
legendary
Activity: 1372
Merit: 1252
I was considering usnig Electrum to create a cold storage setup, however I have been convinced that using anything but a full client is insanity. Look at the recent events as posted by theymos on the sticky:

https://bitcointalksearch.org/topic/electrum-vulnerability-allows-arbitrary-messages-phishing-5090097

Just stick to full blockchains. Get a full client that you can trust like Core, run it in an online computer with no coins, then run another Core client in the airgapped computer. Move raw transactions into the online computer and broadcast them.

I don't see why bother with any other software. "As a newbie" is not really an excuse. Start with the real thing. Developing bad habits its not good in Bitcoin.

There's no arguing that Core is better than any other wallet, but it's wrong to dismiss other wallets. Electrum has been around for years, it was reviewed by many people, it's one of the most popular wallets, and for a reason.
Almost every software has some bugs, this is a reality. When a serious bug was discovered in Core client earlier this year, people didn't say that it's insane to use Bitcoin, we just accepted that software is not perfect.
The recent Electrum vulnerability didn't render it broken in a sense that attackers could easily steal private keys, it abused error massages from servers to execute a social engineering attack. If you are using it as cold storage, you would be unlikely to get affected because you'd need to get through many steps - first you'd need to broadcast a transaction on your watch-only Electrum wallet that is connected to a malicious server, than you'd need to download a malicious client and install it on your air-gapped machine, and only then your coins would get stolen if you sent some coins again.

Bitcoin ecosystem remains a harsh place for unexperienced people, and for anyone involved it's important to develop a deeper understanding of cybersecurity.

Plus let's be in the reality that not all Bitcoin investors will be patient or motivated enough to run bitcoind/Core wallet, and download the blockchain. That was one of the causes why we have other tools that were developed for the community, such as Electrum.

For purely cold storage purposes, I believe the guide is as good as the user's ability to secure his seeds.

You can't really compare the bug that was found in Core, which was theoretical at best, and fixed anyway before it even had a chance to do anything.

The Electrum bug as explained by theymos sounded as if you were just a click away from losing your coins:

Quote from: theymos
This message is false, sent to you by a hacker. If you click the link in the message and install the software, then your BTC will be stolen.

When has Bitcoin Core had anything like that? I mean fuck, I could have believed that was a real update myself and click on there. At least if you are going to use Electrum with Tails, be sure to download the latest one, check the gpg keys, and disable internet when generating the wallet, then create a watch-only wallet and put the private keys in cold storage to never see the internet again. This also requires a level of expertise, at the end of the day there are no shortcuts to Bitcoin security. I understand not wanting to download the entire blockchain but you will still need the watch-only/airgap private keys dual setup as a must.
legendary
Activity: 2898
Merit: 1823
I was considering usnig Electrum to create a cold storage setup, however I have been convinced that using anything but a full client is insanity. Look at the recent events as posted by theymos on the sticky:

https://bitcointalksearch.org/topic/electrum-vulnerability-allows-arbitrary-messages-phishing-5090097

Just stick to full blockchains. Get a full client that you can trust like Core, run it in an online computer with no coins, then run another Core client in the airgapped computer. Move raw transactions into the online computer and broadcast them.

I don't see why bother with any other software. "As a newbie" is not really an excuse. Start with the real thing. Developing bad habits its not good in Bitcoin.

There's no arguing that Core is better than any other wallet, but it's wrong to dismiss other wallets. Electrum has been around for years, it was reviewed by many people, it's one of the most popular wallets, and for a reason.
Almost every software has some bugs, this is a reality. When a serious bug was discovered in Core client earlier this year, people didn't say that it's insane to use Bitcoin, we just accepted that software is not perfect.
The recent Electrum vulnerability didn't render it broken in a sense that attackers could easily steal private keys, it abused error massages from servers to execute a social engineering attack. If you are using it as cold storage, you would be unlikely to get affected because you'd need to get through many steps - first you'd need to broadcast a transaction on your watch-only Electrum wallet that is connected to a malicious server, than you'd need to download a malicious client and install it on your air-gapped machine, and only then your coins would get stolen if you sent some coins again.

Bitcoin ecosystem remains a harsh place for unexperienced people, and for anyone involved it's important to develop a deeper understanding of cybersecurity.

Plus let's be in the reality that not all Bitcoin investors will be patient or motivated enough to run bitcoind/Core wallet, and download the blockchain. That was one of the causes why we have other tools that were developed for the community, such as Electrum.

For purely cold storage purposes, I believe the guide is as good as the user's ability to secure his seeds.
legendary
Activity: 3024
Merit: 2148
I was considering usnig Electrum to create a cold storage setup, however I have been convinced that using anything but a full client is insanity. Look at the recent events as posted by theymos on the sticky:

https://bitcointalksearch.org/topic/electrum-vulnerability-allows-arbitrary-messages-phishing-5090097

Just stick to full blockchains. Get a full client that you can trust like Core, run it in an online computer with no coins, then run another Core client in the airgapped computer. Move raw transactions into the online computer and broadcast them.

I don't see why bother with any other software. "As a newbie" is not really an excuse. Start with the real thing. Developing bad habits its not good in Bitcoin.

There's no arguing that Core is better than any other wallet, but it's wrong to dismiss other wallets. Electrum has been around for years, it was reviewed by many people, it's one of the most popular wallets, and for a reason.
Almost every software has some bugs, this is a reality. When a serious bug was discovered in Core client earlier this year, people didn't say that it's insane to use Bitcoin, we just accepted that software is not perfect.
The recent Electrum vulnerability didn't render it broken in a sense that attackers could easily steal private keys, it abused error massages from servers to execute a social engineering attack. If you are using it as cold storage, you would be unlikely to get affected because you'd need to get through many steps - first you'd need to broadcast a transaction on your watch-only Electrum wallet that is connected to a malicious server, than you'd need to download a malicious client and install it on your air-gapped machine, and only then your coins would get stolen if you sent some coins again.

Bitcoin ecosystem remains a harsh place for unexperienced people, and for anyone involved it's important to develop a deeper understanding of cybersecurity.
legendary
Activity: 1372
Merit: 1252
I was considering usnig Electrum to create a cold storage setup, however I have been convinced that using anything but a full client is insanity. Look at the recent events as posted by theymos on the sticky:

https://bitcointalksearch.org/topic/electrum-vulnerability-allows-arbitrary-messages-phishing-5090097

Just stick to full blockchains. Get a full client that you can trust like Core, run it in an online computer with no coins, then run another Core client in the airgapped computer. Move raw transactions into the online computer and broadcast them.

I don't see why bother with any other software. "As a newbie" is not really an excuse. Start with the real thing. Developing bad habits its not good in Bitcoin.
sr. member
Activity: 279
Merit: 435
Really interesting post.

Just thinking . Few things:

- Tails has lots of software that could potentially have a backdoor. Similar to what happened with nodejs package for bitpay exploit
- Also electrum itself has lots of python packages dependecies which is uncessary overhead just for seed creation

Is it possible to generate a secure seed using just simple linux commands without electrum. Can we have a barebones Unix with just basic booting packages and tools and then do this just by commandline ?
Hi,

The seed is derived from a private key from a known algorithm available here so you can make an implementation in another way.
The private key from which the key is derived is just a random number. On Linux you could generate a private key this way (omitting order of the curve) :
Code:
darosior@debian:~$ hexdump -n 32 -e '8/4 "%08X" 1 "\n"' /dev/random
F2D2655A037B2E53802DC02EEEE8C4E58F51D7532E6FF955A695D7457C6D3CC2
But there may be better sources of entropy.
jr. member
Activity: 80
Merit: 2
Cheaper than burning a laptop and more paranoid way:
1. Buy $2 Arduino or $10 Raspberry Pi without any network connectivity
2. Connect monitor and keyboard and boot basic Linux from sd card
3. Open command line and type source code of your cryptocurrency public/secret key pair generation function from printed github page
4. Write down the result
5. Destroy your $10 microchip investment
6. Huh
7. PROFIT!
hero member
Activity: 692
Merit: 569
Really interesting post.

Just thinking . Few things:

- Tails has lots of software that could potentially have a backdoor. Similar to what happened with nodejs package for bitpay exploit
- Also electrum itself has lots of python packages dependecies which is uncessary overhead just for seed creation

Is it possible to generate a secure seed using just simple linux commands without electrum. Can we have a barebones Unix with just basic booting packages and tools and then do this just by commandline ?
legendary
Activity: 2898
Merit: 1823
Or write down your seeds on a piece of paper or cardboard, and try laminating it yourself. There are lots of "do it yourself" guides on the internet.
hero member
Activity: 672
Merit: 526
legendary
Activity: 3430
Merit: 3080
Isn't Tails' main feature that it is amnesic and doesn't leave any data between sessions (aside from opt-in persistent storage)? Or any other live OS would act in the same way?

If it's not explicitly designed to do so, another LiveOS might allow some session data to survive, but this is only possible if using a writable medium like USB flash (and hence why I mentioned using CDs as a failsafe; you don't even have to worry about Tails having a data persistence bug if you run it from a CD, it's not possible for any data to be written to the CD accidentally or by design)


1. Download Tails, and make a bootable USB with it.

2. Boot Tails on an offline computer.

That works, of course. But there's no particular reason to use Tails, since you're staying offline. Tails is only different from other live os'es when using it online, any live os would work for this purpose.


But Tails Linux already has Electrum as part of its set of tools that is already pre-installed.

Ah, I didn't know that.
legendary
Activity: 3024
Merit: 2148

That works, of course. But there's no particular reason to use Tails, since you're staying offline. Tails is only different from other live os'es when using it online, any live os would work for this purpose.


Isn't Tails' main feature that it is amnesic and doesn't leave any data between sessions (aside from opt-in persistent storage)? Or any other live OS would act in the same way?


This should be obvious, but Electrum which included on Tails isn't up-to-date. Bug regarding wallet/seed creation don't happen and new address/wallet standard rarely changed, but people should know about this fact.


I've installed Tails on a USB one year ago and it had some really ancient version of Electrum, something like 2.7.9. It obviously couldn't open my SegWit wallets so I had to install a newer version brought from another USB drive.

if someone is really paranoid enough to do something like this then they must also be paranoid enough not to trust Electrum itself specifically its random number generator engine. for these people using computers is not a good suggestion.
instead they can use physical ways of creating their private keys using dice, coin flip,... there are also enough articles about how to use these methods too.

Paranoia can be dangerous if it is combined with lack of fundamental knowledge, such people can end up creating their own crypto, generating weak random numbers or just simply encrypting too much and then losing their keys.

For me, what works better is an air-gapped/never touched the internet VM in virtualbox , in which I've installed a downloaded and signature-verified copy of electrum as my cold wallet.


VM's can't be considered air-gapped, if the first layer is pwned, all next layers are pwned too.
newbie
Activity: 18
Merit: 7
For me, what works better is an air-gapped/never touched the internet VM in virtualbox , in which I've installed a downloaded and signature-verified copy of electrum as my cold wallet.

I put the related XPUB in my regular-use/online computer as a watching-only Electrum wallet.

A transaction is pretty easy....create the unsigned tx, put it on a trusted USB and insert to the cold VM...sign it, return it to the watching wallet, and broadcast.

I'm as paranoid as about anyone, so my Electrum wallet connects to my own Electrum Personal Server installed on my own full bitcoind node.

Easy, and secure.


I
copper member
Activity: 2940
Merit: 4101
Top Crypto Casino
1. Download Tails, and make a bootable USB with it.

2. Boot Tails on an offline computer.

That works, of course. But there's no particular reason to use Tails, since you're staying offline. Tails is only different from other live os'es when using it online, any live os would work for this purpose.



6. Burn the USB. If you are very paranoid, burn the computer too.

Or just use a USB based CD drive. USB flash drives are susceptible to their own class of malware, CDs are a better tech if security is the aim (CDs can be made read-only)


Also, if you're already feeling paranoid, burning USB drives (or computers) in your back yard (or anywhere) could make you feel worse. And also make you appear a little suspicious to anyone who notices you doing it.

Sorry, but just to add that a USB can be set up with "read only".
legendary
Activity: 2898
Merit: 1823
1. Download Tails, and make a bootable USB with it.

2. Boot Tails on an offline computer.

That works, of course. But there's no particular reason to use Tails, since you're staying offline. Tails is only different from other live os'es when using it online, any live os would work for this purpose.


But Tails Linux already has Electrum as part of its set of tools that is already pre-installed.


6. Burn the USB. If you are very paranoid, burn the computer too.

Or just use a USB based CD drive. USB flash drives are susceptible to their own class of malware, CDs are a better tech if security is the aim (CDs can be made read-only)


Good point. CDs are more recommendable. But USB drives are also "ok enough" because they will never be used online.

Quote

Also, if you're already feeling paranoid, burning USB drives (or computers) in your back yard (or anywhere) could make you feel worse. And also make you appear a little suspicious to anyone who notices you doing it.


Hahaha. Ok, maybe destroying the USB drive, and the computer's RAM through the microwave oven might be enough.
legendary
Activity: 3290
Merit: 16489
Thick-Skinned Gang Leader and Golden Feather 2021
4. Back up your seeds, and addresses.
I'll skip ideas for backing up the seeds, that has been discussed in many topics.

How do you store the addresses, and how can you be absolutely sure nobody has altered them for their own address? A digital copy is not enough, if you encrypt it you need to use an offline system again, and if you write it down in your own handwriting it's very annoying to use.
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