[REDACTED]

[hZti]

I would prefer an iPhone about basically any computer wallet, simply because there are way less attack vectors. This does not mean that an iPhone can replace hardware wallets or that I would be comfortable to store large amounts, but still it is an option if you are just beginning with bitcoin and don’t want to invest to much money.

An old iPhone can also be „airgapped“/kept offline if you don’t need to spend coins easily.

[dkbit98]

Correct. I think mobile phones cant replace hardware wallet features. Btw, still Im interested in knowing about this saga phone's price since it claims to be a blockchain based device (I know even HTC tried this before and failed) , where can one buy it ? Is there a thread about it in the forum? Specs ? Anyone? If someone got any legit source, you may post it here.

I don't know where you can buy that crap and I don't know any spec, research it yourself.
This is just shitcoin junk device that will certainly die soon enough after they collect more money from people.
If you want to waste your money go for it, but don't expect to receive any security of device updates from Saga ponzi scheme.

An old iPhone can also be „airgapped“/kept offline if you don’t need to spend coins easily.

Not really.
You can only be sure something is really airgapped if you remove parts that communicate with cell towers and internet.
I do however agree that old phones can be useful for bitcoin.

[Becassine]

Is there a way to add hardware into a phone that is separate from the phone itself but can still interact with it from the inside to sign transactions and truly keep your bitcoins in your phone?

The BitBoxApp is available on Android so you can manage your crypto on the go. Simply download the Android app and connect your BitBox02 using the convenience of USB-C.

I don't know if you were thinking of something like that, but maybe it looks like it.

In this case you have indeed two devices : smartphone and cold wallet, but if you don't have a pc, it's still very practical and above all very secure.


https://shiftcrypto.ch/app/

[NotATether]

There's no reason to attempt something like this, because a phone just runs an OS like a desktop does, and needs companion software to interact with the wallet anyway. In other words, it would not be a real hardware wallet, because it is connected to the internet, Bluetooth, NFC, and everything you would not want cold storage to be touching.

It's better to just stick with old-fashioned and stand-alone hardware wallets that have worked so well for us up to now.

[Z-tight]

An old iPhone can also be „airgapped“/kept offline if you don’t need to spend coins easily.

Yes a phone can be turned into an airgapped device and used to store BTC, but it has to be done correctly, in a very safe enviroment. I recommend that one should just buy a good hardware wallet if they do not know how to securely set up an air-gapped device, some people set up this cold storage device and still connect it to the internet, that is a terrible decision, it should be totally disconnected from the internet, with airplane mode turned on and Wifi disconnected. It is easier to use a hardware wallet than this method, only use it if you cannot get a hardware wallet.

[hZti]

. It is easier to use a hardware wallet than this method, only use it if you cannot get a hardware wallet.

Old smartphone is usually free but a hardware wallet will cost you at least 50 usd. So I can see why people would consider a smartphone.


Even if a iPhone can be kept offline easily (just reset it and not safe any Wi-Fi passwords on it) I think it is still pretty safe if you connect it every few months to quickly send some coins. But that is just my personal opinion.

[Z-tight]

Old smartphone is usually free but a hardware wallet will cost you at least 50 usd. So I can see why people would consider a smartphone.

Using an air-gapped phone for cold storage is a good option, but only if you can set it up and use it in a safe environent, if you cannot, then buy a hardware wallet, $100 for a hardware wallet should not be a problem if you are storing anything from $1000 upwards.

I think it is still pretty safe if you connect it every few months to quickly send some coins. But that is just my personal opinion.

This is the worry when people use air-gapped devices, they can lose their funds with one mistake or just bad operational security. Your air-gapped device should never be connected to the internet, the risk of losing your funds when you connect it to the internet is surely always there. It is very easy to send funds out of your air-gapped wallet without internet connection, all you need is another online watching-only device, this device would created the transaction, which your would import into your offline device through scanning the transaction QR code, then you use your offline device to sign the transaction and export it back into your watch-only device, and then you broadcast. Read the links below for more understanding on how to do it.

https://electrum.readthedocs.io/en/latest/coldstorage.html
https://bitcointalk.org/index.php?topic=5237614.msg54149363#msg54149363

[hZti]

. Your air-gapped device should never be connected to the internet, the risk of losing your funds when you connect it to the internet is surely always there.

Well yes obviously this is the correct answer if you want to know what would be the textbook solution to this question. If you however store such low amounts of bitcoin that it is not an option to buy a hardware wallet then this is still a good working solution. Remember that bitcoin was designed without hardware wallets in mind and has worked flawlessly for many years before hardware wallets.

[sheenshane]

. Your air-gapped device should never be connected to the internet, the risk of losing your funds when you connect it to the internet is surely always there.

Well yes obviously this is the correct answer if you want to know what would be the textbook solution to this question. If you however store such low amounts of bitcoin that it is not an option to buy a hardware wallet then this is still a good working solution. Remember that bitcoin was designed without hardware wallets in mind and has worked flawlessly for many years before hardware wallets.

I tend to agree, air-gapped and hardware weren't there before and AFAIK, the first Bitcoin wallet was the Bitcoin core which was released in 2009 and then a hardware wallet came up in the year 2014 and that was a Trezor one.

For me, as long as it is a non-custodial wallet and I have full control of the private key considering I'm safe especially if that is only a small amount.  An electrum wallet would be fine.

However, to answer OP's question.
Have you heard SikurPhone?  It runs on a modified version of the Android operating system which you can use as an air-gapped wallet.

[Z-tight]

Remember that bitcoin was designed without hardware wallets in mind and has worked flawlessly for many years before hardware wallets.

Sure, but when BTC was also created there was no SegWit or Taproot address, there was also no Layer two solution like the Lightning network. The BTC network could not have remained exactly the way it was when it was created, that is why there are so many improvement proposals and recommendations for better security. There are also maintainers and developers who ensure that the network is running smoothly, and anyone can also check for bugs and report them, it is a community thingy for best security and compatibility possible.

However, Electrum on an online device is enough if the money you want to store is small and for spending often. When BTC was created it was not really worth stealing, that is why hardware wallets and better security recommendations were introduced when BTC's value began to increase.

[dkbit98]

Have you heard SikurPhone?  It runs on a modified version of the Android operating system which you can use as an air-gapped wallet.

I think that SikurPhone is outdated closed source junk and I would never used it as an airgapped device.
This phones reminds me a lot on those FBI made  ANOM phones that criminals used for ''safu'' fake encrypted communication.
Best alternative device I know is opensource Graphene OS that works with any Google Pixel phones, and everyone can install it and verify very fast.

[hZti]

Sure, but when BTC was also created there was no SegWit or Taproot address, there was also no Layer two solution like the Lightning network.

Yes that is very true and I am myself a user and fan of hardware wallets. However I still fully belive that bitcoin is also secure in its original state that does not requiere a hardware wallet at all. I know people that own less than 50 USD worth of bitcoin and they will be for shure better of with and old phone as a "hardware" wallet than to not use any precaution at all.
In general I always tell people to use a hardware wallet of course, if the investment is big enough to justify it.

[Aikidoka]

We already know that we can use a phone as a hardware wallet if it's air-gapped and never connected to any network. It's essentially the same thing as a hardware wallet, but it's a cheaper/free option if you can't afford to buy a hardware wallet. For example, you could set up an offline Electrum wallet on an old Android phone and keep it safe and air-gapped.

Yes that is very true and I am myself a user and fan of hardware wallets. However I still fully belive that bitcoin is also secure in its original state that does not requiere a hardware wallet at all. I know people that own less than 50 USD worth of bitcoin and they will be for shure better of with and old phone as a "hardware" wallet than to not use any precaution at all.
In general I always tell people to use a hardware wallet of course, if the investment is big enough to justify it.

Bitcoin is highly secure in its original state, as you mentioned, but the problem can arise from a person's behavior and the way they use their wallet. Security is no joke when it comes to your money and assets, so everyone should be careful and take all the necessary security measures to keep their Bitcoin wallet safe.

[taufik123]

-snip-
Best alternative device I know is opensource Graphene OS that works with any Google Pixel phones, and everyone can install it and verify very fast.

Graphene OS looks good, I just found out about it.
But it officially only supports Google Pixel and the latest one already supports Google Pixel 7 Series.

It is indeed open source and anyone can develop it.
Looking at this Graphene OS forum and searching about implementation on other devices such as Xiaomi, Samsung etc.
Requires substantial Kernel development knowledge, AOSP development skills, resources, as well as considerable time to start porting on the desired device.
https://discuss.grapheneos.org/d/2482-can-grapheneos-be-built-for-other-devices-such-as-xiaomi/2

I used to do ROM porting for Android devices, but for Graphene OS it looks more complex and not easy to port.
This is also related to the security system in it.

Which devices will be supported in the future?
https://grapheneos.org/faq#future-devices

Besides Graphene OS, there are 2 more OS, LineageOS and CalyxOS.
have their own advantages and features.

[bettercrypto]

As far as I know it is possible to add hardware to an iphone if it is separate from the iphone itself, that can still interact with it from the inside to sign a transaction to keep the bitcoin on the iphone Which is called a hardware wallet.

      You probably know that a hardware wallet is a device that stores bitcoins offline, which you can connect to your phone via usb or and once you do it, you can sign transactions without showing your private key.

[taufik123]

As far as I know it is possible to add hardware to an iphone if it is separate from the iphone itself, that can still interact with it from the inside to sign a transaction to keep the bitcoin on the iphone Which is called a hardware wallet.

You may have misunderstood the OP's intention. He wants a hardware Wallet that is directly embedded in the smartphone and becomes one like the Solana Saga Smartphone, not a separate wallet or Hardware wallet in general.

      You probably know that a hardware wallet is a device that stores bitcoins offline, which you can connect to your phone via usb or and once you do it, you can sign transactions without showing your private key.

A Bitcoin wallet stored offline would indeed be better and more secure than a Wallet that is constantly online on a smartphone.

The optimal and recommended use of crypto wallets is hardware wallets.
Without internet or other wireless connections WIFI, Bluetooth.

[dkbit98]

Graphene OS looks good, I just found out about it.
But it officially only supports Google Pixel and the latest one already supports Google Pixel 7 Series.

Yes, but you can buy older Pixel devices that are still updated on regular basis, something like Pixel 5 is fairly cheap and affordable for most people.
There are other alternatives for Graphene OS that work with other Android devices but they are inferior compared to GOS and updates are not so frequent.
LineageOS, CalyxOS, Divest, etc are all fine and open source, but support for other Android devices is not great, and they often get broken with new updates.

[Synchronice]

Overall, smartphone as a hard wallet is a bad idea and I really hope that companies and people don't support it. At the moment, one rarely thinks that someone has a hardware wallet in his smarrphone but imagine, if it becomes popular, a phone theft rate will dramatically increase because bitcoins are like: once gone, gone forever and if we keep in mind the low security of smartphones (doesn't matter which method you use, especially on androids), then the answer is clear.

Do you mean that inside your phone there is a "cold storage build-in wallet" or just a wallet that connects to hardware wallets?
I think Galaxy S10 can do that and I read somewhere that they have a phone that works as a full node, syncs, and you can run it as cold storage but I don't remember the exact name.

That was HTC.

Do you mean that inside your phone there is a "cold storage build-in wallet" or just a wallet that connects to hardware wallets?
I think Galaxy S10 can do that and I read somewhere that they have a phone that works as a full node, syncs, and you can run it as cold storage but I don't remember the exact name.

You are probably talking about the Samsung Blockchain Wallet, although I have never heard talks about it being a full node.

It's not a full node. Just a simple wallet. It also comes with Samsung Blockchain Keystore.

[tabas]

Ledger Nano X has its mobile app through its Ledger live app and it supports iOs and android OS. Well, they're in the hot seat now thanks to their new added feature which is the ledger recover and it's good for everyone to know about it and there's a continuous discussion all about it.
Thread: Ledger Recovery - Send your (encrypted) recovery phrase to 3rd parties entities
While this has just given me the idea of what OP is looking about. I've personally thought of this actual smartphones are hardwallets by simply downloading a wallet like Electrum mobile and keeping that phone offline, the same goes for those laptops that are used as an actual wallet for those that can't afford to buy a hardware wallet or chooses to use that with their spare laptop and keep it disconnected from the web as if it's an actual huge hardware as their wallets.

[Pmalek]

If OP is still interested, they can take a look at what the AirGap wallet is doing with its most recent service called AirGap Knox.
https://bitcointalk.org/index.php?topic=5342004.0

I am not advertising the service or anything, just mentioning it here because I heard about it recently. AirGap Knox is a device manager you install on your phone that blocks connectivity on the OS level and thus keeps your phone offline. However, it's a paid service and closed-source.