Thoughts on Bitcoin transactions without internet connection

So, I've been thinking about how we could potentially do transactions without needing the internet, like using Bluetooth or radio waves. It's been on my mind for a while. Just a heads up, I'm not sure if there's already a system like this out there or if there's something better. If you’ve seen anything similar, let me know. I came up with this concept I’m calling CapsuleChain. Just a name that I thought fits the whole idea! Here’s the gist: in the future, there might be a wallet that’s just an electronic device, and this battery-powered gadget could send and receive Bitcoins through Bluetooth or other frequency waves. What I’m envisioning is that the Bitcoin BTC code would act like a capsule, which you could later connect back to the main blockchain when online. This device would have a limit on how many Bitcoins you can send at once and how many it can hold for transactions each day. Think of it like an old-school money bag that can’t carry an endless amount of cash. To break it down further: there’d be a tech similar to the Bitcoin blockchain or subchain running on this device, which would be open and secure like blockchain should be. Each device would need to have the software set up from an online source before it could handle transactions. The catch is that the device wouldn’t work until you’ve set up this CapsuleChain from the original source. And we’d have to implement various security measures like passwords, mobile codes, or OTPs to keep everything safe.

If there is no Internet access, there is off grid transaction solutions. [Total privacy Bitcoin]: off grid Transactions LoRaWan/goTenna. There are developments and solutions but I think in modern societies, don't have Internet access is only temporary situation when you hang out somewhere too remote. Otherwise, you can have Internet access quite easily and if you have something important to do, broadcast your transactions before you have any remote holidays and prepare some cash to use too.

Your explanation details how the new created versions of Bitcoin would be transacted on your Capsule chain, but you failed to provide a means of synchronizing them to and fro the bitcoin Blockchain through hopefully Bilateral anchoring. You should know that to achieve an effective Side chain like you're proposing, it should be based on real main Chain bitcoins which means the UTXO would be locked on main chain using probably multisignature wallet while it's corresponding tokens are created simultaneously on your side chain, so that you can use it freely on the side chain nodes without Internet, and when you want to unpeg/unlock the UTXOs on the main chain, the corresponding tokens on the side chain should be adequately destroyed to maintain Bitcoin supply and then you'll be needing the Internet. I believe that this implementation breeds a lot of centralization if I'm correct, and if course there's no total ownership of funds by users and which isn't the best way to use Bitcoin.

Why complicate this so much?  Spending in a similar way is already possible.  Have an offline wallet on you, sign a transaction, the shop keeper only has to broadcast it for you.  The purpose of 'offline transactions' is particularly that you should not have to rely on the internet to spend your Bitcoin.  Having an 'offline capsule' that you have to connect before and after spending to the internet, not only will it not be a successful product considering most people do not have Bitcoin and most of the few people who have Bitcoin do not spend it physically, but it is also pretty useless if you ask me.

In recent times, Something similar was also introduced in South Africa whereby you can make a transaction without the use of internet, you may have to see this one in South Africa https://www.forbes.com/sites/digital-assets/2023/03/15/how-africans-are-using-bitcoin-without-internet-access/ also, something related had been discussed already on the forum from the reference here am sharing https://bitcointalk.org/index.php?topic=5545764.20 I don't know how the safety could be with your own idea using Bluetooth or infrared, but we have to be security conscious and not to create a loophole.

Here are some advantages, such as: 1) Bitcoin will only be transacted between two devices, so there will be no fear of delays. 2) Carrying small amounts of Bitcoin will be safer and less risky. 3) Since there is no internet connection, the risk of hacking is low, so everyone can be interested in transacting. 4) There is no problem even if the device is lost or stolen, because the code will be linked to the subchain (if no one knows the password, even if they get the device, they will not be able to transfer Bitcoin).

They are not advantages to me, If I sign a Transaction offline and you broadcast it for me, it still happens only between two devices.  Bitcoin Transactions are instant, the only delay depends on how many Confirmations it takes before you consider it to be final. You can limit your self from having too much Bitcoin in your Wallet.  What determines the upper limit of how much Bitcoin you should hold?  Is it a fixed Fiat amount converted to Bitcoin?  If Bitcoin has a 50 percent drop, you can now have 50 percent less USD value to spend around the city. My option of signing a Transaction offline and having the cashier broadcast it for you does not involve an Internet connection either.  It only does for the cashier, but he has no direct interaction with my Wallet, he only scans a QR code I generate. I can be a thousand miles away from my home and lose my phone and I would still be able to recover it using my Seed. ----- What would stop me from having two such devices with the same code on both and going to Store A with the first one, spending my Bitcoin off the first device, then going to Store B and spending off the second device?  If my devices and the ones used by the store are all offline, until they all go online and one of my transaction is conflicting with the other there is no way they can find out.

Ideas are always welcome. However, it should be compliant with Bitcoin's protocol and provided with simple/technical details on how it works, not just the end-user workflow that you provided. Or if it needs to change something (hard-fork), the required changes to the protocol should be provided. And I don't see any of those details on the OP. (what data are being exchanged via Bluetooth, how can you deposit to the mini wallet, etc.) Probably why you posted this in Bitcoin Discussion instead of Development board, no? Unfortunately, technical details are the hard part and asking others to fill in the missing parts for you isn't going to work unless the idea is actually interesting and deemed viable. Are you under the impression that bitcoins are stored in the wallet? That's why you mentioned "deposit" when talking about the max amount? If no, and you understand how UTXO work; then explain how can you make it safe to keep non-broadcasted transactions that's kept offline in the "CapsuleChain" since the payer can just drop it and never broadcast it to the network once he connected it to his main wallet. Or will it work differently, please elaborate. Someone might find this interesting if you actually managed to give a satisfying answer.

Via Bitcoin (Subchain / CapsuleChain) A capsule code is made into a small code (points), which when decoded by the (subchain\capsulechain) will return Bitcoin! In this case, if the code is decoded, then the capsule code of that device can be decoded by the (subchain / capsule chain) account. That is, a capsule / mini code will be sent which can be decoded by the (subchain / capsule) chain account and brought from the capsule to Bitcoin. For example, let's say a buyer loads 0.05 Bitcoin to his device through the buyer's capsulechain / subchain account. Now the transfer Buyer's device TO Seller's device TO Seller's subchain account will decode TO Bitcoin (I don't know if such a method can be done directly with Bitcoin)

You will need to look at available Bitcoin side chain projects that can give you some more technical information and ideas as you are interested in developing your Bitcoin subchain with whatever name you choose for it. Sidechain Observer - Bitcoin L2 Projects & current state of development. I am not interested in such side chains because with me, Bitcoin on chain, main net is good enough to use for my Bitcoin transactions especially in recent months, Bitcoin mempools are very good so that Bitcoin users can use 1 sat/vbyte and lower sat/vbyte fee rates for their transactions without too long waiting time for confirmations from Bitcoin miners.

Count me out of this idea. Did you forget that technically Bluetooth and frequency waves RF can be intercepted through the air. Information's can be hijacked and be rebroadcasted to another channel. Anyone with the right tools, just have to be within range to get a hold of the signals. Scammers and hackers will surely get it easier through this method. This is literally going back to the past not moving into the future. Bitcoin should not be more complex than it has already been after so may BPIP proposal. In the meantime. I will do more research on the pros and cons on this idea. In all, the idea is welcoming but I dont think people will be safer using Bitcoin on other chain, the Mainnet is ok to them.

Wireless stuff like bluetooth/RF can be intercepted if not secured well, there's actually some risk there. But I think it also depends on how it's implemented, with proper encryption its not just like easy to hack or something. Still, you're right that adding more layers can make thing more complex and risky for users. I think mainnet is the safest and simplest option for now.

I do think that the LN has more than compensated for this ideology but the disparity is in Internet connectivity of which the LN relies on. Since the idea of OP leans more towards offline transactions, the concept being brought into realization may enable more adoption mostly in rural areas with good cheap devices and better battery life also, where there's inefficiency of internet providers and quality access to the Internet.

I doubt something like this would ever be created, but I think offline transactions are very important for any payment system. One alternative is to have printed bitcoin paper bills with preset amounts, or something like Satochip Satodime bearer cards that can be loaded with any amount of coins.

It looks similar to Grin Coin, where you can make an offline transaction and send it to the receiver via Bluetooth or via message or email. Actually, Bitcoin has ways to make an offline transaction and broadcast it to a separate device, but it's not the same as this because you need two devices: one with no internet connection and the other online where you can create the unsigned transaction and transfer the file via Bluetooth to the offline device to sign the transaction and send it back to the online device to broadcast the transaction. It is still an offline transaction, not similar to what you mentioned, but it is a safe method to prevent keys from being exposed on the internet.

I honestly have a hard time imagining where on my country such location would exist. At worst mobile internet access is readily available, although the speed and price vary. And if you only need them for making transactions, I doubt you need a connection with high-speed. Then again, if your location is so remote, are offline payments with Bitcoin going to be common?

What about Led Blinking method, QR code or flashing pattern or camera capture with very near one device to another device? Do you have and think about it? Let me knkow it is possiable way! ( device to device with qr or pattarn code scan )

You idea is a good one but theory has a lot of loopholes. you seem to forget that in Bitcoin, ownership isn't just like some kind of capsule that you can just pass around from one person to another like some file, when a transaction is made, it becomes a shared record that everyone needs to update together. Let's assume you are able to come up with this kind of offline wallet, and who people exchange some amount of BTC, how exactly can you really protect yourself from the double spending problem? I mean how would you know whether the same value that's been spent in that transaction hasn't already been spent somewhere else? And even if you limit the amount to 0.5BTC, it still doesn't make the risk of double spending disappear, it only reduces the damage.