Offline mode/No internet/Local Area only mode/off the grid support? #461

Hi!

I'm a currently(hopefully-only-temporarily) disabled person who just wants to message/call another person in a different room of their house over Wi-Fi(no internet).

I'm using the cwtch 1.7.1 on my Windows computer and this other person is running cwtch-v1.7.1.apk on their Android phone.

Is there some way where we could send messages to each other without having to connect to the internet?

I've looked for FOSS alternatives. And to the best of my knowledge there aren't any.
Briar, at the time of writing, isn't available on Windows. Linux Desktop only :(
In Manyverse, at the time of writing, the messages don't always show up immediately(even though it's just over local wi-fi) and you have to manually refresh and, there are no notifications(audio or otherwise), yet.

I know cwtch doesn't do calling yet, but even just messaging(with some customizable audio notification) offline over Local Wi-Fi(no internet) would be great.

Please help me?

It has been extremely difficult finding fully offline FOSS calling/messaging software. Which was quite surprising, because I would think(from a technical standpoint) that it would be comparatively easier looking for other devices to "talk to" over LAN than over the internet?
Unless I'm mistaken? If so, feel free to correct me.

Thanks!

Hi!

Thanks for opening this issue.

While I am not strictly opposed to developing such a feature for Cwtch, I'll try and give some background for why this isn't the easiest feature for us to offer.

The main goal of cwtch is metadata resistance which means our primary focus has been on distributed parties who need to communicate securely - rather than locally-routed decentralized messaging.

The problem with adding such a feature is that locally routed messages have essentially no-anonymity and thus significantly diverge from the main engineering and design principles behind cwtch - all communication in cwtch is routed through the anonymous communication network (ACN) stack and so developing this feature ultimately means rewriting that stack to allow for less-secure hooks (in a way that doesn't accidently subvert the security model) - or introducing a highly sandboxed local-only "ACN" interface that runs concurrently to the main stack.

There is also the possibility of introducing a new ACN stack that makes it easier to run a local network version (e.g. something like niwl - https://git.openprivacy.ca/openprivacy/niwl - although that is arguably much more work)

All are doable in theory, but all require heavy secure-design consideration at pretty much every layer in the stack from networking to UX - and given that this isn't our main priority, and the current overall lack of funding for Cwtch I need to stress that this is unlikely to happen in the near future without a significant change in one of those areas.

All that being said, we do have plans for local communication to facilitate syncing between multiple devices, and it might be worth considering this request in that context (e.g. extending the domain of "trusted" devices further to allow a "local group" chat).

As such we will keep this issue open for the time being - and consider it in upcoming planning / funding allocation.

Thanks again.

Sarah