The topic of digital privacy is of great importance, but also quite complex. Calling something "private" can mean different things to different people — anything from "trust me bro" to full end-to-end encrypted communications.

There are two main areas covered by Flotilla where privacy requirements and guarantees differ: community spaces and direct messages.

Space Privacy

Flotilla approaches digital privacy through a pragmatic lens, relying primarily on self-hosted community infrastructure to protect privacy rather than encryption. This allows community organizers to have greater control over exactly what content remains private, and who has access, rather than setting the rules for your community in stone through encryption.

As a result, spaces are as private as the policies enforced by the relays that host them. If a relay administrator prefers for the space to be invite-only and private, they can enforce that. If they prefer their community content to be read-only for non-members, that's an option too. The important thing is to communicate that expectation to community members.

Groups are only as private as the least trusted member. As members join a group, the guarantee that messages won't be shared out of context weakens dramatically. Protecting the privacy of a 50-member group using encryption would be overkill, given how week the groups privacy along a social dimension is likely to be.

It's also worth mentioning that because Flotilla is built on the Nostr protocol which uses digital signature to verify messages, it has weak deniability. What this means is that if content is leaked from of the group, it can be proven that it is authentic, because it was digitally signed by the author.

For this reason,we like to describe Flotilla's groups (particularly those hosted by Coracle Hosting or using the Zooid relay implementation as "non-public", rather than "private". Flotilla is not a solution for journalists or activists, but for small communities.

Direct Messages

With that said, Flotilla takes a different approach for direct messages, which represent a much more private form of communication. Because direct messages don't usually include more than a handful of participants (Flotilla supports small group chats as well as one-on-one conversations), it does make sense to protect them using encryption — particularly since DMs are often stored on public infrastructure.

To that end, Flotilla uses the NIP 17 standard for end-to-end encrypted direct messages. The result is that not only are service providers unable to see your conversations, you also have deniability and metadata protection.

The thing that Flotilla DMs do not have however is either forward secrecy or post-compromise security. In simple terms, this means that if your Nostr identity is ever compromised, it can lead to the attacker having access to old messages.

This represents a compromise between user experience and security — implementing these stronger security guarantees would also mean your messages would not be available when signing into a new device.

The Future of Messaging

In the future, Flotilla may support an emerging standard being pioneered by the team at WhiteNoise called Marmot. This new protocol has all the features of strong encryption mentioned above, as well as the ability to host larger groups.

The standard is very new, and porting many of Flotilla's more sophisticated group management functionality to it would be a long process, so for the moment we are not actively adopting it, although we hope to in the future. In the meantime, if you're looking for a solution with better privacy guarantees, try WhiteNoise!