Bitcoin w/o internet \ stacker news ~bitcoin

689 sats \ 20 comments \ @timechain 2 Oct 2022 bitcoin

Hey, I started writing on the subject of using Bitcoin w/o local internet, or when only one side has internet, or using HAM radio, SMS, Starlink, Blockstream Satelite, meshnet, mailing someone an opendime... any way bitcoin has been sent under these kind of non-typical ways.

If you folks know of any more lesser known projects or experiments like this, sending a link to any article/writeup/website/video/podcast would be appreciated.

My goal is to raise awareness of progress that Bitcoiners have made to deal with future possible no internet, low internet, or sporadic internet situations. In doing so, maybe encourage more work in this field. Internet shutdowns and slowdowns for political reasons are becoming more common.

Note: I have already googled the hell out of "Bitcoin without internet," "offline Bitcoin," "Lightning offline," that kinda thing.

Thanks, and have a great night!

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194 sats \ 4 replies \ @ek 2 Oct 2022

I have used the Bitcoin SMS relay before:

https://rusnak.io/how-to-send-bitcoin-transactions-via-sms/

Just send a signed transaction to +1 (863) 248-2646 or +1 (863) BIT-COIN.

Unfortunately, the number is in the United States so it did cost me 0,86€ from Europe (excluding the blockchain fee) but it was worth the experience.

I think there should be numbers for every continent at least.

5 sats \ 3 replies \ @timechain OP 2 Oct 2022

Thanks!!! Heres one of those for Africa. Near the end of the video, they show the numbers for several African countries. https://twitter.com/BitcoinEkasi/status/1562568332783468545?t=O3FhAGpWDQGubEMbs99Qsw&s=19

edit: The one in the video is Lightning (LNURL) . I didnt know they did mainnet sms relay in 2017. Thanks again!

0 sats \ 2 replies \ @KenyaCoin 2 Oct 2022

The one in the video is Lightning (LNURL)

A clarification:

Machankura is a USSD-based custodial bitcoin wallet. The mobile subscriber (user), whether on smartphone or feature phone, interacts with Machankura through USSD menus. The service supports LN deposits (via LN invoice created by website, or via Lightning address). It supports withdrawal ONLY via Lightning address. If the destination is a mobile number, or is to a @8333.mobi Lightning address, the service performs an internal ledger update.

In some of the countries supported by Machankura, a receipt for a transaction will be delivered via SMS, but other than that there is nothing else done with Machankura that involves SMS.

I didnt know they did mainnet sms relay in 2017.

Machankura is a new service. Are you possibly referring to some other service?

30 sats \ 1 reply \ @ek 2 Oct 2022

Machankura is a new service. Are you possibly referring to some other service?

Maybe he means the service mentioned by me since the article is from 2017

30 sats \ 0 replies \ @timechain OP 2 Oct 2022

Yep

71 sats \ 3 replies \ @shyfire 2 Oct 2022

Check out Samurai's TxTenna if you haven't already

0 sats \ 2 replies \ @timechain OP 2 Oct 2022

Yeah, I have that one bookmarked to check out. thank you!

50 sats \ 1 reply \ @shyfire 2 Oct 2022

OK cool. I assume you also have machankura bookmarked? https://8333.mobi/

0 sats \ 0 replies \ @timechain OP 2 Oct 2022

Yep! Thanks!

200 sats \ 1 reply \ @cryptocoin 2 Oct 2022

Satscard, is like an OpenDime where it can be passed person-to-person, offline.

But with satscard the funds can be spent, and then a new address generated. That can be done sequentially for a total of 10 uses: https://satscard.com/faq

There are other approaches with other technologies:

Between a Rock and a Hard Place: Offline Use in CBDCs https://www.progressoft.com/blogs/between-a-rock-and-a-hard-place-offline-use-in-cbdcs

Blockchain side implementation of Pure Wallet (PW): An offline transaction architecture https://www.sciencedirect.com/science/article/pii/S2405959521000928

300 sats \ 0 replies \ @cryptocoin 2 Oct 2022

Scrit (also referred to as Scrit1), which is referenced as "prior art" for Fedimint, has methods for "half-offline" (i.e., only sender online, or only recipient online), and offline (i.e., both offline, and could be done via paper / QR codes even).

"Scrit: A distributed untraceable electronic cash system" https://github.com/scritcash/scrit-whitepaper/blob/master/scrit-whitepaper.pdf

The Fedimint homepage also refers to "Scrit2" with having "receiver- and sender-initiated half-offline transactions".

And along these lines:

Transferable E-cash: A Cleaner Model and the First Practical Instantiation https://eprint.iacr.org/2020/1400.pdf

And there are a number of redeemable code / voucher / etc approaches, including:

LNCash https://ln.cash/how

200 sats \ 1 reply \ @cryptocoin 2 Oct 2022