Oddbean

Mental model: an ecash mint with the purpose of processing payments for a specific service is an alternative to an accounting system. The flow: - user tops up balance (e.g. via Lightning) - service provider (SP) issues ecash to user - user pays ecash to SP for use of service Imagine running an entire blockchain for a single application, a website, social network, VPN provider. That would enable interesting use cases but would be a huge waste of resources. With ecash, you can build these systems without blockchains. Lightweight, fast, and cheap. That is why I'm advocating for businesses to explore these use cases as I see great potential in them, especially in the Bitcoin space. Not only does it guarantee privacy, but it's also easier and safer to build than to have user accounts, passwords, balances, transactions, etc. Closed ecash systems also do not run into risk of being regulated as money transmission services for the same reason you don't have this issue when you use a BTCPayServer for selling a VPN, for example. It's only the service provider who gets paid for its service. I'll be focussing on these use cases as we're developing the Cashu protocol, which allows you to use ecash with Bitcoin. The internet is as bad as it is partially because payments are so bad. Payments forced us to think in accounts and accounts forced us to be traceable.

"The internet is as bad as it is partially because payments are so bad. Payments forced us to think in accounts and accounts forced us to be traceable." 🎯💯 nostr:nevent1qqs2633022jztwc78qsqn5slwsn9j24sm07vkletjy4vsc7ypj7swtgpzemhxue69uhhyetvv9ujuurjd9kkzmpwdejhgq3q2rv5lskctqxxs2c8rf2zlzc7xx3qpvzs3w4etgemauy9thegr43sxpqqqqqqzjmkd82

https://www.keychat.io/ 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. Keychat uses Signal protocol to ensure message encryption security and meta-data privacy

We are pleased to find a very good 【prototype】; people can easily understand the postal system, which allows them to comprehend ecash as e-stamps, Nostr relays as post offices, and the necessity for messages themselves to be end-to-end encrypted. Messages need to continuously update the recipient and sender addresses.

@Dan Are you building keychat? If so, I'd love to chat with you abot how you're implementing the Signal protocol. I have an open PR on the NIPs repo right now to bring Signal like double ratchest to Nostr. https://github.com/nostr-protocol/nips/pull/1206

Hi Jeff. About message encryption, Nostrat fully reuses the Signal protocol (X3DH + double ratchet) and reuses libsignal. First, let's return to the mechanism of the Signal app. The Signal app uses phone numbers as user IDs. When Alice downloads the Signal app and knows Bob's phone number, she adds Bob as a Signal friend by entering Bob's phone number in the Signal app. The Signal server then returns the following data associated with Bob's phone number: Bob's identity key IKB, Bob's signed prekey SPKB, Bob's prekey signature Sig(IKB, Encode(SPKB)), (Optionally) Bob's one-time prekey OPKB. Alice then combines this with her own identity key IKA and her ephemeral key EKA to complete the X3DH operation, and then initiates the double ratchet algorithm to start encrypting messages. When Bob receives the message, he can also initiate the double ratchet to decrypt the message. Let's now assume that Alice and Bob have both downloaded Keychat and want to communicate using it. Bob displays his QR code, which contains his Nostr key and Signal-related keys. Alice scans it. Alice can then complete the X3DH operation and start the double ratchet encryption. It can be said that Keychat, unlike Signal, does not use a server to pass the related Signal keys. Keychat treats the Nostr key as a phone number. If Alice only knows Bob’s Nostr key, she can send a special NIP4 message to retrieve Bob’s related Signal keys.

Sure that all makes sense. I just wrote NIP-104 basically codifying that into the spec. Just curious how your implementation is done. Is your code open source somewhere? Would love to have a look. Have you looked into syncing on multiple devices yet?

Code will be released soon. Keychat doesn’t support syncing on multiple devices. Every device has its own ID. And those devices can communicate through group chat. It’s very hard to support syncing for double ratchet algorithm. More difficult in conditions there is no coordination server.

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

I think this should be the model for some (or even most) nostr relays. Relays are service providers, if you rely on them for reach, why not incentivize them for every post, and since you directly rely, ecash makes more sense nostr:nevent1qqs2633022jztwc78qsqn5slwsn9j24sm07vkletjy4vsc7ypj7swtgpr3mhxue69uhhyetvv9ujumt4w35ku7thv9kxcet59e3k7mgzypgdjn7zmpvqc6ptqud9gtutrcc6yq9s2z96h9dr80hss4wl9qwkxqcyqqqqqqgfgl5fh

@calle 👁️⚡👁️ , is there currently a feasible easy way to build this kind of service-specific credit system without user accounts? For example, if someone wanted to create a website with a credit system similar to a real-life arcade (user buys credits with money, and credits can only be used for the games within that arcade place), how could they get started?

Yo. Check this. `/mint` only. No `/melt`. Maybe `/swap`? nostr:nevent1qqs2633022jztwc78qsqn5slwsn9j24sm07vkletjy4vsc7ypj7swtgpp4mhxue69uhkummn9ekx7mqzypgdjn7zmpvqc6ptqud9gtutrcc6yq9s2z96h9dr80hss4wl9qwkxqcyqqqqqqg4yc5ru

I think one difference is that credits on an account can't be traded for cash, but ecash can be. Amazon vouchers and gift cards can also be traded for cash, but something something FBI! GET ON THE GROUND! or something. I feel like even gift vouchers are going away like cash, and when as it does, its perception as a tool for criminals and the subsequent lack of empathy from the people lead to it becoming criminal.