Compared to unstructured P2P overlay networks, DHTs offer efficient and (theoretically) reliable discovery.
However, they are prone to eclipse attacks and [typically offer weak privacy properties](https://github.com/gpestana/notes/issues/8).
This topic comprises researching novel techniques mitigating or even thwarting [eclipse attacks](https://www.gemini.com/cryptopedia/eclipse-attacks-defense-bitcoin#section-what-is-an-eclipse-attack) against DHTs.
A focus on [Node Discovery Protocol v5 (discv5)](https://github.com/ethereum/devp2p/blob/master/discv5/discv5.md) is of special interest to the Vac team.
Further background on the usage of discv5 in Waku can be found in our [research log](https://vac.dev/wakuv2-apd).
A new version of discv5 that is both efficient and provides eclipse mitigation is [currently being researched](https://github.com/harnen/service-discovery-paper).
### Privacy-Preserving Incentivizations of waku protocols
* Incentivise relay
### Devising novel applications of the Waku protocol stack
[Waku relay](https://rfc.vac.dev/spec/11/), Waku's core protocol, is based on a [gossipsub mesh](https://github.com/libp2p/specs/tree/master/pubsub/gossipsub),
while [Waku discv5](https://rfc.vac.dev/spec/33/) uses a [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) overlay.
Both significantly benefit from robust and reliable P2P connections.
Better connectivity allows nodes to contribute more to the network and improve overall availability, efficiency, and by extension, anonymity ([see k-anonymity](https://en.wikipedia.org/wiki/K-anonymity)).
[NAT](https://en.wikipedia.org/wiki/Network_address_translation) is a well known problem to P2P connectivity.
There are various types of NATs whose behaviours are described in [RFC 4787](https://www.rfc-editor.org/rfc/rfc4787).
[Carrier-Grade NATs](https://www.rfc-editor.org/rfc/rfc6888) add another layer of indirection, which complicates the matter further.
Various [NAT traversal](https://en.wikipedia.org/wiki/NAT_traversal) protocols have been developed to overcome the different types of NATs.
[RFC 8445](https://www.rfc-editor.org/rfc/rfc8445) specifies Interactive Connectivity Establishment (ICE), which integrates a set of NAT traversal techniques.
Waku currently uses [libp2p NAT traversal](https://docs.libp2p.io/concepts/nat/),
specifically [STUN](https://docs.libp2p.io/concepts/nat/#hole-punching-stun) (leveraging the [identify protocol](https://docs.libp2p.io/concepts/protocols/#identify))
and [AutoNAT](https://docs.libp2p.io/concepts/nat/#hole-punching-stun#autonat).
The main focus of this topic is on researching novel ICE-complementary NAT traversal techniques that are decentralized and have desirable privacy and anonymity properties.
The topic also comprises integrating and specifying ICE for [Waku v2](https://rfc.vac.dev/spec/10/).
