Glacier is a protocol for secure cold storage of bitcoins. https://glacierprotocol.org
Just to clarify about the test withdrawals: you can use the same UTXOs you previously printed out (and already spent). You've already demonstrated that you can successfully broadcast a withdrawal transaction. All that's left to prove is that each of your 4 keys will work on this wallet.
How can a non-technical person be confident in any cold storage solution (glacier, Casa, hardware wallets) if they cannot audit the code for themselves? What steps can someone like me take to have maximum faith in Glacier and/or Casa? I know that I could take the time to learn to audit the code, but that would take more time than I have to make a decision about how to hodl most securely
The same problem applies to any Bitcoin wallet software, not just cold storage.
Or really, any software you ever install on your computer. People abusing that trust is what led to malware.
At the same time, any public maintainer is basically announcing to the world that he/she has a large sum of bitcoins. This is not wise.
As a result we have had several anonymous contributors but a dearth of public reviewers and maintainers.
concern about glacier is complexity when it comes to inheritance. I wrote a five page detailed letter to my loved ones already but still have concerns that they would be able to figure it out without contacting an outsider with technical ability.
I’m thinking I should use glacier and hope not to die before a better solution comes out
And provide an exceptional set of instructions to the best of my ability to my non-technical family
I also have concerns about inheritance. I've written a similar letter. One thing I've considered is developing and documenting a low-security withdrawal process for use if all else fails. Glacier is fairly straightforward single-address multisig. The complexity lies in doing it all securely, using the offline quarantined laptops.
I meant to say included in the protocol as an appendix or something
Part of it comes from trusting the review process of Glacier, but a big part comes from limiting the attack surface. If someone were able to compromise GlacierScript, there's not much they could do, since GlacierScript has no control over where its inputs come from, or where its outputs go to. After building a transaction with GlacierScript, you scan out the transaction and send it to coinb.in for validation and broadcast.
So in order for the attacker to extract any info, they would need to compromise both GlacierScript (at the time you build your APP USBs), and coinb.in (at the time you build your withdrawal).
Although -- there is one form of attack that might be possible, a "chosen nonce attack", where the signatures in the transaction can reveal a part of your private key. If the attacker could compromise GlacierScript to create such signatures, they could scan the blockchain for your withdrawals and possibly determine your private key. Since Glacier reuses addresses, this could be effective.
I don't think such an attack is possible IF you use an uncompromised Bitcoin Core for signing transactions. And GlacierScript does so, and it has been reviewed and audited by many people (including myself), so I am confident in its security.
Note: any wallet system will have the same kinds of attack vectors. In this regard, Glacier is better than any other system I'm aware of.
Good question. That comes from GlacierScript itself, specifically this code here: https://github.com/GlacierProtocol/GlacierProtocol/blob/bda9582eda7280f6b154d63eb1c5359ab76fe369/glacierscript.py#L635
Which, if compromised, could generate keys known to the attacker.
But in your view, have even the latest releases Of Glacier been reviewed thoroughly enough to support the idea that the code remains well-reviewed? I know many people reviewed and commented on earlier versions, but that enthusiasm from some of the other contributors dropped off over time. What would keep someone from slipping something malicious into the code now that not as many people are looking? Are all modifications to the code, however small, closely monitored?
You can look at the history of PRs to confirm this: https://github.com/GlacierProtocol/GlacierProtocol/pulls?q=is%3Apr+is%3Aclosed
For anyone who might have private keys stored in bank safe deposit boxes as part of their Glacier Protocol, here's something to consider - I was granted access to my safe deposit box yesterday while wearing a medical mask. I was never asked to remove the mask so that they could verify my identity. Granted, I did still have to show my ID and had to have the key to my box, but it was still a bit shocking. Any person with similar physical characteristics to me could have pulled this off if they had my ID and safe key. This helped me understand that bank safe deposit boxes aren't as secure as I once believed them to be.
I have tested GlacierScript with Bitcoin Core v0.20.0rc2 (upcoming release). No changes needed. (Although, thanks to bug #38, Glacier is broken anyway, and nobody seems to care.)
Guess I have to go through updating to the latest Bitcoin Core. Thanks for this https://gist.github.com/bitcoinhodler/8be823fae7b46e924caa594abdde3bd0 @bitcoinhodler you contribution is very much appreciated.
And thanks for pointing out issue #14, must be this. I'll test it later this week.
I've added a warning to my gist to be careful and do your own research. Don't blindly trust those instructions. They have not been reviewed by the wider Glacier community (if there is such a thing) and if I wanted to be malicious I could direct you to download a hacked Bitcoin Core that sends all your coins to me.