Oddbean

The Introduction of Keychat Keychat is a chat app, built on Bitcoin ecash, Nostr protocol and Signal protocol. Keychat is inspired by the postal system — stamps, post offices, letters. Keychat uses Bitcoin ecash as stamps and Nostr relays as post offices. Senders send messages stamped with Bitcoin ecash to Nostr relays. The Nostr relays collect the Bitcoin ecash, then deliver messages to receivers. Unlike the centralized postal system, Keychat can use multiple Bitcoin ecash issuers and Nostr relays, each maintained by distinct operators. Keychat uses Signal protocol to ensure message encryption security and meta-data privacy. The content of the letter can be exposed easily by opening the envelope. Keychat messages are end-to-end encrypted via Signal protocol, with a unique encryption key generated for each message. Only the sender and receiver can decrypt the message. The addresses of both parties on the envelope can be tracked. In theory, this problem is solved if they change addresses daily. So Keychat reuses Signal protocol to update sending and receiving addresses for nearly every message. Like the postal system, Keychat requires no registration. Users just generate Nostr keys as ID. https://www.keychat.io/

It is interoperable. Keychat relay only add collecting bitcoin ecash function. If the relay operator provides free service, current relays e.g., Damus relay can be used as Keychat relay. The android apk will be released first, then the code.

Agreed, there is no reason to do this. Not necessarily malicious, sometimes people just have bad ideas and/or justify them with bad reasoning. OP, please release the source code as soon as possible; no one cares if it's ugly or half-broken or whatever. When the app is released I might test it out briefly, but for something as important as encrypted comms I won't consider using it regularly until source is available (and ideally it has reproducible builds too).

Keychat message is also kind 4 event. So Keychat can use all relays which supports kind 4. The difference between Keychat messages and DM messages is encryption/decryption methods, which processed in client. Relays don’t care about encryption.

Yes, nostr relays get those ecash stamp. We think there is no long-lasting free lunch. So we learn from postal system. Ecash is best e-stamp. relay will be post office, which has income to cover cost.

Interesting, I just read about the double ratchet algorithm: https://signal.org/docs/specifications/doubleratchet/#double-ratchet Does this mean that users could publish their nsec and their old DMs would not be accessible?

Can the devs stop now please. 😂 Can't keep up anymore. nostr:nevent1qqsdyx8k5my7e9vxzwfr0mz4mutd6kzdg3jk0hmsufj6lg5luwjsqqgpvemhxue69uhkv6tvw3jhytnwdaehgu3wwa5kuef0dec82c33vdhrvdesvcmrvvmwxd4hxvpjdfhxumrnwejr27fc8pax5mn9veunsve5xdukkctcwvmhjvmw0faxket5wfehy6nhwsuxz0mzwfhkzerrv9ehg0t5wf6k2q3qh0uj825jgcr9lzxyp37ehasuenq070707pj63je07n8mkcsg3u0qxpqqqqqqzdwjg40

The onlyProblemm is constantly having to install a new app/migrate friends and famely.... But one day we'll have a absolutely great solution nostr:nevent1qqsdyx8k5my7e9vxzwfr0mz4mutd6kzdg3jk0hmsufj6lg5luwjsqqgpz3mhxue69uhhyetvv9ujumn0wd68ytnzvupzpwleyw4fy3sxt7yvgrran0mpenxqlululur94r9jlax0hd3q3rc7qvzqqqqqqyq5al6v

Sorry! I can't understand why I should pay for messages when I can send messages for free, for example through SimpleX or Briar? Perhaps you meant that when sending messages with stamps, the relay will have an incentive to work and not interfere with sending encrypted messages? And there might even be special relays?

You didn’t write about this on your website, you didn’t say why I should send paid messages. I'm not outraged, I just want people to understand what incentive they might have to use your program.

Take Phoenix LN wallet for example. Fees of Sending via Lightning 0.4 % + 4 sat https://phoenix.acinq.co/faq#what-are-the-fees The fee-free mode of custodial Lightning Network wallets has misled many people into thinking that the Lightning Network is very cheap.

Don't use Phoenix then. If I have $50 of Bitcoin on the Lightning network. I don't care about custody. If I put $1000 of Bitcoin on the Lightning network, I'll make sure I have my own keys. "Bitcoin e-cash" is a misnomer. It's not Bitcoin. It's some shitcoin that may or may not be backed by Bitcoin.

I would imagine the relay operates the mint and since lightning is used to get in/out your client could just use lightning to buy the exact amount of ecash needed for a stamp and then use that? Probably still prohibitively expensive with lightning fees for one stamp but maybe you could just round up to whatever makes sense whenever your balance is too low.

Yeah I don't see it as functionally different than you loading an account somewhere with credits, or a custodial wallet. I think it might be useful as a formalized way for people to spin up an account system within their app/service with lightning in/out and some privacy internally, but still just as risky as holding funds on anywhere else custodially.

There are no lightning stamps. Ecash is bearer asset, lightning does not have anything like that, but it's convertible, it is actually created by paying a lightning invoice. Doing several roundtrips to pay 1 sat (which would be requirement for lightning) is not feasible.

Moar messaging options... nostr:nevent1qqsdyx8k5my7e9vxzwfr0mz4mutd6kzdg3jk0hmsufj6lg5luwjsqqgpzamhxue69uhhyetvv9ujumn0wd68ytnzv9hxgtczyzaljga2jfrqvhugcsx8mxlkrnxvplelelcxt2xt9l6vlwmzpz83uqcyqqqqqqg0zl3hf