Bitcoin Forum

AirGap is an open-source (https://github.com/airgap-it/) audited software wallet that turns your old phone into a hardware wallet. it achieves this by using two apps, called AirGap vault and AirGap wallet.

AirGap Vault: AirGap Vault is a blockchain agnostic crypto vault that turns your mobile phone into a cold wallet.

AirGap Vault does not connect to any network, irrespective of the device used. This system built into the app makes it more secure than an ordinary crypto wallet.

Transactions can be signed seamlessly without the use of cables, thanks to verifiable QR codes. This opens up multiple possibilities for interacting with other solutions and also wallets.

The AirGap Vault is currently used alongside other companion apps like AirGap Wallet, MetaMask, Sparrow Wallet, BlueWallet, Specter, and any other QR code-based wallets. These companion apps serve as watch-only wallets that allow users to view portfolios and initiate transactions while the Vault signs transactions and protect your private keys offline.
.

AirGap Wallet: The AirGap Wallet is a watch-only wallet used alongside the AirGap Vault. This separation helps to provide optimum security while handling your funds.

The AirGap Wallet initiates transactions, connects to a network to fetch data from the blockchain, and displays this information within the app as a portfolio overview. The Vault, however, does not connect to any network, irrespective of the device used. The Vault signs transactions and protects your private key securely offline.

About AirGap features

• Store your private key totally offline with maximum security
• MetaMask Support
• Offline Address Overviewl
• Secure input Keyboard
• Coin Flip & Dice Roll
• Offline Key Generation
• BIP39 Passphrase
• Shamir Shares
• Open Source
• BIP85 Child Entropy
• No KYC requirement to be able to convert coin within the application
• Many more...

COIN SUPPORTED

• All EVM-chain when paired with MetaMask
• Bitcoin(BTC)
• Ethereum(ETH) & ERC20
• Aeternity(AE)
• Groestlcoin(GRS)
• Tezos(XTZ) & FA1.2/2
• Cosmos(ATM)
• Polkadot(DOT)
• Kusama(KSM)
• Moonriver(MOVR)
• Shiden(SDN)
• Astar(ASTR)

I have my old smartphone with Android os version 4.4.2 and I can't turn it into ''hardware wallet'' because i can't install and test this app.

Not really sure what version Airgap is supporting but if they are only supporting new android versions than this story of using old phones is not really true.
I can even read on their google store that even Android 5.1 and Android 8 are not supported, and some user with Android 6 is also having issues.

AirGap Vault and AirGap Wallet require at least Android 5.0. Make sure that the WebView is updated to the latest version.

dkbit98 raised a good point. Anyone who is going to use AirGap wallet is likely going to use an old mobile with an old Android version especially the mobile for the AirGap Vault. And since it is going to be an arirgapped device it would be better if you makeAirGap Vault compatible with old versions than asking the user to upgrade his device which require an Internet connection.
Also, in this guide on how to create a wallet: https://medium.com/airgap-it/airgap-the-step-by-step-guide-bff36d50a4ed it sais you have yo "Use your fingerprint to store the secret in the secure enclave of the mobile device"! is this mandatory? If yes then what about devices that are not equipped with fingerprint sensors?

AirGap requires at least Android 5.0(which is still considered old) and the reason we didn't move further back is that there are some security features that are not available on older devices.

your device will ask for a fingerprint if that's the default security setup you have or pin or pattern as the case may be, so a device without a fingerprint sensor will work perfectly fine.

you can look at the more recent guide from 2019 on how to set up here (https://medium.com/airgap-it/airgap-the-step-by-step-guide-c4c3d3fe9a05)

Your site is not as privacy invading as some other sites that claim to be interested in preserving the privacy of its users, but still there are 3 ad trackers and 2 third-party (https://themarkup.org/blacklight?url=airgap.it) cookies on it.

I have never heard of your brand to be honest. I took a look at the medium article you shared in your latest post and was wondering why does it say that your apps are still in beta and it's not recommended to "handle productive funds with it"?

That guide was from 2019, at that point, it was at a beta state.
It is a fully fledge production app now and it is recommended to handle productive funds.

AirGap is mostly funded by grants from various cryptocurrency foundations.

I saw complains from people on google store claiming they couldn't even use your wallet with Android 5.1, and even if everything looks nice on paper in reality it is not working for all old smarphones.

What I am interested to know is what system and derivation paths are you using for generating seed words and can they be used to recover funds on other wallets like Electrum, Wasabi or other hardware wallets like Trezor?

The majority of the issues we've experienced from our users not being able to set up the app are related to not having an updated webview.

Yes, you should be able to recover your funds with other wallets as long it supports a 24-word seed phrase. (I think electrum uses something different, I'm not sure though).

Also, the code for AirGap is open source, so the default derivation paths are all there. You can also open the Vault and go to the Add Account screen, toggle the Advanced Mode, and you will see the default derivation path for each protocol.

So please tell us what exactly BIP standard you are using and what are default derivation paths for Bitcoin generated by Airgap wallet?

m/44'/0'/0'

If you have more questions can you write to us on telegram or any of our support platforms?

Can you give a brief explanation how the tx's is being transferred from the Vault to the Wallet? (QR Code) without the source being contaminated or altered using Malware?

Would it not be more secure if the tx's could be encrypted between the source and destination? (To prevent a Man-In-The-Middle attack between the two devices? I have been looking for something like this to sweep coins from a Paper Wallet to a online wallet, but the Private Key must be encrypted at all times.  ;)

Currently, we use our own Serializer to encode the data we transfer in an efficient way. It also supports “splitting up” QR codes into multiple chunks, which allows us to transfer transactions with many inputs or outputs that don’t fit into a single QR code.

On our support page, we have a small page that shows a few examples and contains instructions on how the content of the QR codes can be inspected using 3rd party tools. https://support.airgap.it/coinlib/examples/serializer/v2/introduction

A small note here: We’re working on a bigger refactoring of our apps to support Segwit and PSBTs. Once this is done, there will be an option to encode the data in different formats, for example, bc-ur, to be compatible with other watch-only wallets like Electrum or Sparrow.

So that’s just some background information, let’s get to your questions:


We generally assume that the offline device (Vault) can be trusted. If you don’t trust the offline device, you will have to inspect every QR code going from Vault => Wallet yourself (using 3rd party tools) to make sure no sensitive data is leaked. Sadly, this is not as easy as it sounds. By inspecting the contents of a QR code, you might catch some simple attempts to leak private data (eg. if part of the seed is put into the identifier). But sophisticated attacks, for example abusing the “random number” of an ECDSA signature, can leak data in a way that is practically impossible to detect. (See https://core.ac.uk/download/pdf/301367593.pdf). Because air-gapped and offline wallets get more and more popular, we have started a discussion about exactly this issue, but sadly there were no responses so far. Feel free to participate to show other developers that this is an issue we should be looking into: https://github.com/BlockchainCommons/Airgapped-Wallet-Community/discussions/60


Not necessarily. There are advantages and disadvantages to encrypting the messages that are sent between online and offline devices:
   
Advantages:
   

• Privacy (nobody can read the contents of your message)

   
Disadvantages:

• The messages can no longer be inspected by 3rd party tools (at least not with considerable extra work)
• More complexity overall (an additional key/keypair has to be generated for the communication, and it has to be shared between offline and online device)

While encryption obviously also prevents Man-In-The-Middle attacks (if the right encryption is used), this could also be solved by adding a signature to the data. So the only actual benefit of the encryption is that nobody can read its content.

Because of the additional complexity, the downsides regarding verifiability of the messages and no real security advantages, we decided against implementing encrypted messages for now. The thread of a “Man-In-The-Middle” attack is also relatively low in our case, because the communication happens directly between the 2 devices, it is not sent over the network, for example. But we still have it in our backlog to add as an optional feature for those who want it.


While we don’t support your specific use case (we only support BIP39 mnemonics, not private keys), the mnemonics in AirGap Vault are always encrypted, unless they are needed for some action (eg. deriving of the keypair or signing).

Let us know if you have any feedback regarding those points. We’re always happy to have those technical discussions

Can user add erc20 and polka based tokens manually (the ones not listed beforehand)?

Right now that's not possible in AirGap but we will be releasing a new version in few days with WalletConnect functionality, so you can send and receive any ERC20 tokens through something like MEW (connected to AirGap).

I think you could have mentioned the giveaway in your last post.

For those who haven't read their last Medium article (https://medium.com/airgap-it/airgaps-4th-anniversary-and-giveaway-2f459a3f8779), they are hosting a giveaway where 20 random people have the chance to win AirGap metal plates for recovery phrases including electronic engraving pens. To participate, you need to create a video or article about AirGap. Check the article for more information.

This is what you can win:

https://miro.medium.com/max/700/0*9XUdwOKqT6HlIqgm

 

I totally forgot this, Thank you.

Tried to install this to try it out, but when trying to create the entropy for the vault, the camera image freezes and the % stops increasing. So, I can only get to 100% on mic, gyro and touch. As such, I can't actually set up a vault, rendering the entire thing unusable. :-\

Nokia 7 Plus running on Android 10.


Also, does this actually have support for Bitcoin Testnet? ???

Problems with the camera freezing were reported 2 years ago as well. The recommendation back then from one of their team members on githubmemory was to force-close the application and start from scratch.

Here is how to reproduce and solve the issue as reported by the user who experienced the freezing issues:

Source: https://githubmemory.com/repo/airgap-it/airgap-wallet/issues/12

Yeah, I went looking through their github to see if anyone else had a similar problem... it seems that particular issue is actually related to trying to start the QR Code scanner... not the initial vault setup where it is supposedly using video input as part of the entropy generation.

In other news... after leaving it for a day and a reboot or two of my phone due to another (unrelated) app having some camera issues, it seems like it magically started working Airgap Vault... even though a reboot of the device had already failed to fix the issue previously??!? ??? ::)

So, I finally managed to get the vault setup... however, I don't see a way to use TestNet with this. So, I assume I would need to edit some code and compile my own APK etc :-\

I'm not sure what the issue is regarding the camera, maybe it's a temporary issue with your device.


We don't support bitcoin testnet for now. If you can do that, it will be perfect. Another thing you could do is to open an issue on the AirGap Github page.

I just had a quick glance at your most recent article about keeping your seed safe. Among the recommendations, you mention that one should be careful not to write down their seed in a place that has cameras and microphones. It makes sense paying attention to cameras, but what about microphones? Do you know of an instance where a microphone (more precisely a maliciously configured microphone) was able to capture sensitive data such as recovery phrases, and how exactly? The only thing I can think of is being recorded if you are saying the seed words out loud.

Here is what was written


People back up their seed phrases in different ways. One of which is memorizing them. In this process, people tend to recite these words so they can stick to their memory. Such a case is an instance where one needs to be careful of microphones.

I see that Shamir Shares are available in AirGap wallet, but is this compatible with Trezor and Keystone Shamir scheme?
Big disadvantage for AirGap is that you don't support multisig, but I see that it's coming soon.
One more problem I see with AirGap is Android OS and all various versions and stores, I don't know what oldest Android OS is supported by AirGap, but it is limited with that.
I can't install and test AirGap on my android phone with older Android OS version :P

PS
You may want to update your discord link on that medium article, it's showing Invalid Invite error message.

Both of them ^{[wallet (https://archive.fo/jeNHZ#selection-2313.0-2321.10) and vault (https://archive.fo/0T6nu#selection-2275.0-2283.10)]}, support Android Lollipop ^[5.0] and up.

If "only" one of your phones is suffering from an old Android version, you can try the "web version (https://medium.com/airgap-it/airgap-web-version-f770b4787054)" as well.

The same goes for the other discord link in OP!
^{- For those that are interested to join, "this link (https://discord.com/invite/MG4jUEAJMr)" works [screenshot (https://i.imgur.com/yNWRvOi.jpg)].}

Old device I have is before Android 5 Lollipop version, I think it's something like 4.4 and it can't be upgraded anymore or flashed with different operating system.

I didn't know that Airgap web version exists, but I see that it is somehow connected with ledger hardware wallet, that defeats the purpose of using Airgap wallet.

You're right ^{[not sure how I missed that part when I posted that link the other day]}, but I don't think that completely defeats the purpose of using the AirGap Wallet, since you still have the option to "sign the transaction with the AirGap Vault app ^{[from an offline device]} (https://miro.medium.com/max/6208/1*72OzqU-7d-Fpdl0RUmMzJQ.png)"!

Hey, Thanks for the feedback.


No

Trezor and Keystone use SLIP-39. The disadvantage of this scheme is that it is not compatible with BIP-39, so it is not possible to have a "single mnemonic representation" of a SLIP-39 secret. Our shamir shares are compatible with BIP-39, so it is possible to have both a single mnemonic and shamir shares. In the near future we are planning to use the SSKR standard, which is inspired by SLIP-39, but adds BIP-39 compatibiltiy: https://github.com/BlockchainCommons/Research/blob/master/papers/bcr-2020-011-sskr.md

I understand that both Trezor and Keystone are using Shamir scheme that is connected with SLIP-39, but I could always recover this if I lose one of the wallets, or one of them stop productions and shuts down servers.
What happens if Airgap wensite or app is down and servers gone?
I think that compatibility with other wallets is extremely important for something like this.

This means that in future even Android version 5 won't be supported with new updates, so I would have to use some new phone device, and I don't like this.
I do understand there are some limitations with writing code for older versions, but newer phones have their own disadvantages.

AirGap Vault does not connect to any servers, ever. So there is nothing we can shut down from our side that would stop the app from working. The code of our shamir implementation is open source, so even if we take down our website and github, the code will still be available in forked repositories. If you are concerned about this, you can also create a local copy of the entire source code.

We agree that standards should be used whenever possible, but our implementation pre-dates the final SLIP-39 standard. At the time, there was no standard available. Today, because of the SLIP-39 shortcomings, we are planning to use SSKR, which was introduced by blockchain commons and will hopefully be the new standard going forward and replace SLIP-39 in the long run.

I don't know much about back-end stuff, but the link you provided earlier, it doesn't label AirGap as reproducible ^{[it says "OBFUSCATED (https://archive.ph/6tbbA#selection-201.0-201.10)" instead]}.
^{- On the same page, it mentions that having such things in open-source wallets is considered a "red flag (https://archive.ph/6tbbA#selection-1161.0-1161.65)"! Am I missing something?}

AirGap does not use any form of backend.
We are aware of this issue and we are looking into it. Here is an explanation from one of our dev.
https://github.com/airgap-it/airgap-vault/issues/103#issuecomment-972687269

The following list might come in handy if you weren't looking for free reviews and mentions by lesser-known YouTubers:
^{Note: I prefer to not vouch for any of them + only a few of them have active accounts on this forum!}

• 100 Cryptocurrency Youtube Channels (https://blog.feedspot.com/cryptocurrency_youtube_channels/)

Thank you but this guys ask for ridiculous amount of fees to do Youtube videos that's why we are looking for something more community driven.

I am not so much interested in metamask, but is Sparrow wallet, Blue wallet and Specter wallet only supported Bitcoin wallets, and there is no support for Electrum?
This is one of the most popular bitcoin wallets and there is both desktop and mobile version available.

---

I have one old-new smartphone and I was thinking of testing it with AirGap.
My question is, do I have to disable all internet connection, wifi, remove sim cards, when using this mobile with AirGap wallet?
I didn't saw any explanation about this in step by step guide.

PS
I would suggest adding Vault app to open source android stores like Fdroid or IzzyOnDroid.

It's been two years since they announced (https://www.reddit.com/r/Bitcoin/comments/kj4998/comment/gha0ewi/?utm_source=reddit&utm_medium=web2x&context=3) that AirGap Vault is considering adding support for Electrum, Wasabi, Blue Wallet, and Specter. The vault has in the meantime become compatible with all of the mentioned wallets expect Electrum. It's either the next one on their to-do list or they are struggling with making it work and have given up on the idea of making a connection with Electrum.

That would be odd, since wallets are often based on Electrum, such as using the same derivation path, QR codes, creating the same type of signatures and following other standards that have all been set by Electrum.

Yes, Sparrow, Blue Wallet, and Specter are Bitcoin wallets. We do not support Electrum for now.

We use BC-UR QR code standard and electrum doesn't support it.


This is only necessary for the device with the vault. The Wallet is meant to be on an everyday device with a network.

There were some build issues that we were unable to resolve, mostly because of time constraints, so the issue was closed. https://gitlab.com/fdroid/rfp/-/issues/1479

We'd still like to have AirGap on f-droid, so we'd appreciate any help there.

All this different QR standards are just making more confusion and regular people don't really care about them.
How hard is to make it compatible with this BC-UR QR code standard along with others you support currently?
I am sure you could create some conversion process for compatibility, and I have seen other wallets and signing devices doing the same.

I'm not a developer, so I can't say how hard it is to implement, but from what I can see from our previous implementations, I assume it's a pretty complex process. AirGap already supports BC-UR and that is pretty much the standard for signing BTC transactions. So if in the future, Electrum implements this, we will automatically become compatible. If you have some experience implementing QR codes, you could make a pull request on our GitHub.

This splitting of seed phrase words into multiple parts sounds a lot like Shamir Secret Sharing, but you are not really eliminating single point of failure like you said in your video.
Other dangers of using something like this is that there is no standardized implementation for this method, math can't be verified by different participants.
It's much better to use regular Multisig solution that is proved and tested for years, but I would like to see some documentation for your Social Recovery feature.

So I'm guessing that being an offline wallet, it can't send transactions by itself, only generate them. So how does the "pairing" with the other wallet software work for broadcasting such a transaction?

Is it entirely automated, or does a user have to manually go to the other wallet software for broadcasting stuff?

That's exactly what it is.


Having only the seed phrase is a single point of failure. Introducing a mechanism to recover the wallet even if you lose the seed phrase eliminates this


In the future, we will be implementing something more standardized like SSKR and Seed XOR.


https://support.airgap.it/features/social-recovery/

---

The AirGap Vault signs a transaction and provides a QR code for the signed transaction. The wallet to which it is paired (e.g AirGap Wallet, Metamask, Sparrow, Spectre, Rabby) scans the QR code and broadcasts the transaction.

---

[moderator's note: consecutive posts merged]

Than it's much better to call it with it's real name instead of inventing something like Social recovery feature.
It is also important for compatibility to say if your Secret Shamir Scheme is compatible with one that is available in other hardware wallets like Trezor Model T and Keystone wallet.

Yes it is, unless you add multiple passphrases, but we are talking about improving something and removing single point of failure, that was not accomplished with SSS because one guy controls everything.

That is better, but I don't know who currently uses this except maybe Coldcard.

Can you make a comparison between your Social recovery feature VS Shamir Secret Sharing VS Threshold Signatures Schemes or Multi-Party Computation, for example? Why are your methods better and recommended compared to the ones mentioned? MPC is something I recently heard about, but it's in connection with an altcoin that I don't want to be accused of shilling if I mention it. It's easy to find on the first page of a Google search and the project begins with "Q".   

Hi. I'm Andy, one of the developers on the AirGap project.


There are 2 reasons why we called the feature "Social Recovery" instead of "Shamir's Secret Sharing".

1. The term "Shamir's Secret Sharing" is known in some parts of the community, but because of the lack of a clear standard (at least at the time when we added the feature many years ago), we didn't want users to make false assumptions, eg. regarding compatibility with other implementations (there were a few CLI tools but they were not compatible with our implementation).
2. The term "Social Recovery" is clearer for less technical users.

As already mentioned above, our scheme is not compatible with any other implementation, eg. Trezor or Keystone. The main reason is that our implementation is older than the finalised SLIP-39 standard, which is used by Trezor and Keystone.

The reason we did not change to the SLIP-39 standard after it was finalised is because SLIP-39 does not allow to split up an existing 12 / 24 word mnemonic. So it does not allow you to go from BIP39 mnemonic => Shamir Shares => BIP39 mnemonic. With our implementation, this is possible.

But now that the SSKR standard was defined by blockchain commons, we are planning to adopt it in the near future.


You are right, SSS does not remove the single point of failure regarding mnemonic usage, but it does solve the single point of failure regarding secret backup and storage.


As far as I know, only Coldcard supports Seed XOR at the moment. Hopefully more wallets will follow soon.


As mentioned above, the Social Recovery feature is just a name we use for our implementation of the Shamir's Secret Sharing scheme. I don't know much about Threshold Signatures or Multi-Party computation so I can't talk about them. But from what I've heard they sound very interesting and could solve a few problems.

So if I set up a social recovery option, and then AirGap wallet with all its services ceases to exist 5-10 years from now, how can I regain access to my funds if the scheme doesn't work with other hardware/software wallets? If you adopt the SSKR standard at one point in the future, does it affect all previously configured social recovery setups? Those created before your adoption of SSKR or whatever other model you decide to go for?

The code of our apps is completely open source and the part of the social recovery is only a few lines of code. I would recommend that you use an old deployed version of the app (eg. an APK from GitHub). You could also run the project yourself, or someone could build a standalone version of the recovery feature.


SSKR is a completely separate standard, so it is not compatible with our implementation. Once we add SSKR, the generation part will be replaced completely, so going forward it will only be possible to create SSKR shares. But our apps will always support recovery of "old" social recovery setups, we'll never remove that.

Both reasons you mentioned are proof that people should not use and trust any form of Shamir's Secret Sharing.
Lack is clear standards and confusion between different implementations are big disadvantages, and this was never widely accepted by bitcoin community.
Sure it can be better in some cases than holding simple paper with seed words, but this could be mitigated with one or more passphrases.
Adding extra complexity with obscure incompatible system is no go for me, and until I see compatibility with other wallets I don't think it's safe enough to use Airgap wallet social feature.

How does that even affect funds recovery though, because the Airgap tools are open-source so there is no risk of them disappearing anywhere (as opposed to, say, an exchange or closed-source wallet).

I didn't mean disappear with your money and take it from the users. They said that their scheme and implementation isn't compatible with anything else. So if you set up a social recovery option on AirGap, Airgap is the only software that works with that system. Electrum is open-source, but you can no longer connect old versions to Electrum servers. It's for your own security, but I am just making a point.

My question is what is going to happen with a scheme that is incompatible with any software/hardware wallet we know today if tomorrow everybody at AirGap abandons ship and the wallet simply dies? I got the answer that someone would have to create their own software supporting the social recovery feature and hope it works. That's what I expected to hear as well. 

Lack of clear standards was indeed a problem. But the new SSKR standard is here to solve that. While it's currently not widely used, there are multiple implementations available in case one project shuts down. And adoption will probably improve over time (it's a very new standard).

The use cases for passphrases and Shamir's are very different. But even if you could somehow "replicate" some kind of social recovery feature by using passphrases, that wouldn't be a standard either, and you then have to make sure you remember how to recover it.

And you have to differentiate between not being able to recover your seed in case a project ceases to exist, and having to put some effort into recovering your seed. Our code is open source, so you will always be able to recover it, it's just not as easy as downloading a different app.

But as I said, we do want to build on standards, and now that there is one (SSKR), we'll add support for it in the near future.

Trezor and some other wallets are using Secret Shamir Sharing for years but I don't see general acceptance from community like it happened with their BIP39 proposal.
I doubt this is going to popular with one universal standard, because there are clear flaws in this concept, so it's more likely we are going to see something totally new instead.

I prefer multisig setup, so my question is does Airgap wallet support multisig setup and can it be combined with Electrum and other hardware wallets for this?

Could you elaborate on the clear disadvantages of Shamir's Secret Sharing? The only downside I see is the complexity of the implementation, which leaves room for error and can decrease security if not implemented right. For this reason, we will also add other schemes like SeedXOR and Hamming Backups, which are much simpler and leave less room for error.

In my personal opinion, the reason that SLIP39 did not get a lot of traction was because it is not compatible with BIP39. What I mean by this is that it's not possible to take a BIP39 mnemonic, then split it up into SLIP39 shares and get back your BIP39 mnemonic (=> no "roundtrips" are possible). SSKR is compatible with BIP39 mnemonics. From a wallet developer perspective, adding SLIP39 is more work because it often isn't compatible with the existing architecture of the app. But SSKR can basically just be added as a small add-on, then once the BIP39 mnemonic is recovered, the app can be used as usual. But I guess only time will tell what happens around adoption of those standards.


Multisig has advantages over Shamirs', the most important is that there is no one "single point of failure", because the keys can be distributed while signing. The one important downside in this context is that multisig isn't chain agnostic. Bitcoin supports multisig "natively", but for most other chains, smart contracts have to be used for multisig. So it's not possible to have a generic multisig implementation, but it is possible with Shamirs' because it works on a mnemonic level.

AirGap Vault does support multisig because it supports signing PSBTs. To do this, you'll have to use it with a watch-only wallet like Sparrow, Specter or BlueWallet. Please note that we didn't officially announce the support for multisig just yet, because we would like to add some additional functionality to make it more secure (eg. being able to register co-signers in the Vault to verify change addresses, which currently can't be done). This is on our roadmap and will hopefully come sometime in Q1.

Yes I can, and I wrote more about it one of my topics called Multisig VS Shamir Secret Sharing (https://bitcointalk.org/index.php?topic=5328606.0), so I don't want to repeat myself.
You can clearly see the pros and cons for both of them, and I provided links for reference, but I also listened to comments of some crypto security experts about this subject.

OK good to hear, maybe you should write more about it when it's ready.
There is general lack of mobile wallets that support multisig, and I constantly see people are asking for this.
Can you post link or screenshot for AirGap roadmap?

The starter kit comes at a very attractive price, but if I were you, I would've sent a sample to "Jameson Lopp (https://twitter.com/lopp)" for performing various stress tests and publishing the results ^{[might come in handy in attracting customers]}: Metal Bitcoin Seed Storage Reviews (https://jlopp.github.io/metal-bitcoin-storage-reviews/)

This is is great price for two stainless steel plates and engraving pen in starter kit, but I am interested to see how durable would engraving hold compared to all other stainless steal plates.
I would support suggestion from SFR10 and you should really send your plates to Jameson Lopp who is testing them all the time, and maybe he finds some weak spots.
My favorite backup solution is stainless steal washers that are cheap and durable, but I think AirGap Recovery Plate can easily compete with competition.

$25 is a good price for two metal seed plates especially if they pass all the durability testing with flying colors. Free shipping worldwide is a highly commendable option you have given your customers. I am not sure about the t-shirts though. I don't see a big market for that.

Your shop accepts payments via credit cards and a stablecoin I have never heard of called uUSD. Do you have any plans to support bitcoin or some of the more popular altcoins? PayPal would also be a good option for those not comfortable entering their credit card details in a random website.

On a different note, the link in your post doesn't take us to the shop. It takes us to your Twitter page announcing the shop, and from there we get the link to the shop. Maybe it would be better if the link took us to the AirGap shop directly.

---

uUSD is a stable coin issued on the Tezos blockchain. YOU can learn more here: Youves (https://youves.com/)
Bitcoin and other altcoins are possible. I will forward this suggestion to our devs.



Thanks. I added an extra link to the post.

Does Airgap Knox keep the phone permanently in offline mode with no option for the user to bypass it and turn connectivity on again? Or can I simply turn it off with a click of a button and connect my phone to the internet if I please? As I understood, Knox is a device manager, but a closed-source one, which might not suite many people. Has anyone tested and verified the safety and authenticity of the software?

I have literally had one device of the ledger and another wallet installed on my phone for a very long time. I never stumbled upon your thread or was not around this section a lot to know this one. I will surely use this software to turn my old device into a hardware wallet. My method of doing it air-gapped is very simple, you turn it off and don't turn it on until you want the funds out of it. Lolz. Very poor method to work with it but so far it's far better than my ledger. I lost the ledger once and also found it but obviously one could not forget the big old mobile device laying around which just lost.

I will graciously download the AirGap Knox on my device which I have dedicated for the same purpose mentioned. I will try to turn it into a hardware wallet with your guide and hopefully will write down a review here or in the new thread itself. Thanks for this. :)

That's not how airgapping works, and your phone won't be airgapped just because you turned off the internet and other connectivity. You have to wipe the system first and reset it to factory settings. After that, you install this Knoq solution while configuring your phone, and you never go on the Internet again.

You losing your stuff isn't a measure of the quality of those items. You can rightly argue you don't like Ledger for their closed-source nature, poor built quality, the database hacks, etc. But they have nothing to do with you misplacing the device.

It's like saying my new Nike sneakers are awful because they fell off my balcony. I don't like them anymore.

Knox is a device manager built on Android Enterprise. It disables all forms of connectivity on an OS level ( this is what you don't get by turning your network off & on). so when using Knox you do not have to worry about those kinds of stuff getting on by mistake, in fact, with knox, you only have access to AirGap Vault on your device.

Here are other videos/blog that better explain how to set up knox and what it is.

How to setup AirGap knox: https://www.youtube.com/watch?v=SB4Rq6RlaIs

How AirGap knox looks and feels: https://www.youtube.com/watch?v=_0NL5W_gqy8

https://medium.com/airgap-it/airgaps-newest-product-airgap-knox-3dbf7592533f

Thanks, man, we are looking forward to your review of the entire AirGap solution. Just to clarify, Knox is a device manager, while the AirGap Vault is the center of the AirGap solution that keeps your funds offline. BTW, Knox only works with AirGap Vault.

This looks interesting, and I would consider testing how this works with another older smartphone device I have, but than I saw this should be paid $35.90 and I am not sure if source code can be verified.

Can AirGap Knox be installed on any Android devices, included devices with custom ROM's or Pixel phones that operate with GrapheneOS (not that I would do that), or stock Android must be used?
Correct me if I am wrong but I think we can achieve something similar to disable everything on software level, and for little more money we can already buy brand new hardware wallets.
One more question... can AirGap Knox be removed from device and how?

knox is only the lockdown of the device, and builds on top of the Android security model. The actual manager of the secret is AirGap Vault and this is 100% verifiable and even the first wallet ever to receive the reproducible the wallet scrutiny score


Knox is meant for Android enterprise devices. which comprises over 550+ devices as of today.

https://androidenterprisepartners.withgoogle.com/devices/#!?device_categories=knowledge_worker


Hardware security models aswell as the security design in general of mobile devices is way more secure and battle tested compared to the currently available hardware wallets.

The reason is, these devices don't have the privilege of "not care" about the physical attack vector, yet everyone wants to use them them for very security relevant tasks (mobile banking, identity management, etc)

The knox lockdown performed is one step deeper than what is offered to the user through i.e. settings. Also user errors (i.e. accidentally turning on wifi) are taken care of by the lock down.

Maybe that is the case but they only have security updates for few years at most, I think apple has 5 years, samsung flagship devices has 4 years, cheap phones 1 or 2 years, and than they become unsecure.
Since Airgap wallet is based on older device, that means that most of those devices are generally unsecure.

So is there a way to revert changes to default state with Reset phone function, and remove AigGap later if we changed out minds?

According to the last FAQ on https://airgap.it/airgap-knox/, there is a reset feature that converts the phone back into a standard Android device. 
@Pearson12 Does it require a password or other type of authentification to reset AirGap Knox and uninstall the device manager?

Yes, old models are less secure than new models, but nothing stops the user from using a new model. We started with the idea "based on older model" but some of the libraries we use now require users to use more recent OS, which in turn requires them to use new models.


Yes, there is a factory reset button. After factory resetting, your devices comes back to normal.

No further authentication is required to Reset the device. Here is a video that shows how the reset is done. https://www.youtube.com/watch?v=0h12Y_HhQQI

Is it possible to exchange Bitcoin for cash, or only bank accounts and credit(debit cards are accepted?
I checked out your latest blog post and mtpelerin website but I couldn't find anything about that information.
This is cool stuff and I am supporting anything kyc-free, but I don't get it why should anyone use air-gapped devices for selling/buying bitcoin.

EDIT:
OK, i found Selling Crypto page on Mtpeleri with more information:
https://www.mtpelerin.com/support#selling

Any one using Airgap Wallet already. its been 3-4 days i am still undecided which wallet is good to buy for long term.

I only had a brief experience ^{[e.g. tests]} of using their wallet, so my answer shouldn't matter, but it was good ^{[if you're a newcomer to this field, you might have an easier time with some of the traditional HWs]}.
^{- If you ever decide to use this wallet, make sure all of your devices make the cut: Android (5.0 and up), iOS (12 and up)}

i will go first with Keystone 3 Pro. i read many positive feedback about it. later will try Airgap.