ipfs-nucleus VS ContactDiscoveryService

The block auth is very generic, just an extra top level key in cbor maps or a small prefix in raw blocks. The protocol is S3 V4 signatures.

There is a Java implementation of the modified bitswap for this in Nabu [0] and a Go one in ipfs-nucleus [1]. With both of these you can use whatever auth verification protocol you like.

[0] https://github.com/peergos/nabu

[1] https://github.com/peergos/ipfs-nucleus/

I love this part: https://github.com/Peergos/ipfs-nucleus

I've tried IPFS before but I hit a bug when using it so gave up on my idea for a side project. Might give this a go!

Yep, we built a super minimal ipfs replacement - ipfs-nucleus (https://github.com/peergos/ipfs-nucleus) with added block level access control, which is also post-quantum.

It's actually a mixture of Java, Go, and JS. E.g. all the P2P stuff is handled by ipfs-nucleus: https://github.com/peergos/ipfs-nucleus/

No one needs to install IPFS. Peergos automatically installs and manages it's own IPFS instance. It's actually a super minimal drop-in IPFS replacement - ipfs-nucleus (https://github.com/peergos/ipfs-nucleus) with extended access control. Self hosting instructions are here: https://github.com/peergos/peergos#usage---self-hosting

[1] https://signal.org/blog/private-contact-discovery/

Signal uses SGX for remote attestation, which presumably lets the client verify that the code running on the server is a build of the OSS code and not a modified version. But I don't know the details or if this is reliable.

SGX and remote attestation described here:

https://signal.org/blog/private-contact-discovery/

Signal does private contact discovery and the effort they've gone to to do this is quite impressive.

TEEs have numerous privacy-enhancing applications that may benefit users. One of them is, as discussed earlier, private contact discovery; the Signal application uses a contact discovery service enhanced using Intel SGX, a TEE technology, to protect its users' privacy. A similar application of TEEs is performing malware analysis in a remote cloud service, so that the service may not identify users by the contents of their devices, such as the applications they have installed, especially important as 98.93% of users may be uniquely identified by the list of applications they have installed.

Signal (or, more accurately, one of its predecessors) used to use client-side private set intersection for contact discovery, but this scales poorly [1].

Now they use a solution based on Intel SGX and server-side trusted computing [2].

[1] https://signal.org/blog/contact-discovery/

[2] https://signal.org/blog/private-contact-discovery/