Shout outs to nostr:nprofile1qqsth7fr42fyvpjl3rzqclvm7cwves8l8l8lqedgevhlfnamvgyg78spp4mhxue69uhkummn9ekx7mqpz4mhxue69uhk2er9dchxummnw3ezumrpdejqavh2c0 and Flotilla ( nostr:npub1jlrs53pkdfjnts29kveljul2sm0actt6n8dxrrzqcersttvcuv3qdjynqn ) for having done the most work in this space. Still a lot to do to get private groups/communities to scale!

Chachi ( nostr:nprofile1qqs8lft0t45k92c78n2zfe6ccvqzhpn977cd3h8wnl579zxhw5dvr9qppemhxue69uhkummn9ekx7mp0qyv8wumn8ghj7enfd36x2u3wdehhxarj9emkjmn99ucx20jd ) also a solid runner up just because it's helped me find bugs in other apps faster 😭

nostr:nevent1qqspffhh2cfr3axgy3hp4ygxv5443yat2343l9n5huf98l4jae7urvcpr4mhxue69uhkummnw3ez6er9wch8wetvd3hhyer9wghxuet54fxzef

the NIP-29 relays support private groups in the sense that only allowed members can read and poast to them. these are not encrypted group chats btw. is that what you are looking for?

We think there are two main approaches to implementing private groups on Nostr. The first approach uses access control to ensure that only group members can retrieve notes, without using encryption. NIP-42 is based on this idea. However, this approach relies on the relay. The second approach is end-to-end encryption. You can refer to the comparison note we wrote for an overview of different group encryption schemes.

In terms of how notes are displayed, groups can be categorized as *chat groups* or *feed groups*. Based on member relationships, private groups can be divided into friend groups and topic-based groups among strangers. For friend groups, pairwise group or MLS (Messaging Layer Security) is suitable. For topic-based groups among strangers, shared key group and MLS are appropriate choices. Chat groups are better suited for friend groups, while feed groups work better for topic-based groups among strangers.

Whitenoise by nostr:nprofile1qyfhwumn8ghj7ur4wfcxcetsv9njuetn9uq3jamnwvaz7tmswfjk66t4d5h8qunfd4skctnwv46z7qgewaehxw309aex2mrp0yh8xmn0wf6zuum0vd5kzmp0qy3hwumn8ghj7enfd36x2u3wdehhxarj9emkjmn98ankcmmzv9kr6ctvdshsz9nhwden5te0wfjkccte9e4x2enxvuhxv7tf9uqzq9eemymaerqvwdc25f6ctyuvzx0zt3qld3zp5hf5cmfc2qlrzdh0t6lycm uses strong encryption for privacy within groups. Currently kind of a signal alternative but it could scale to larger groups. However, there is always a social trade off to be aware of. The larger the group, the less trust exists within the group, and the less consequential privacy on the technical level is.

I also think that the relay requirement is an acceptable trade off, since large groups are usually going to have a sufficiently committed admin that will be motivated to run a relay, while smaller groups can thrive in a more informal encryption-supported scenario. The relay requirement may actually be a beneficial barrier to entry that discourages insufficiently motivated would-be community organizers from starting.