Kadmelia is well known DHT but by time its becoming outdated, some of the attacks for example happened by study done on I2P that doesnt has real solutions within it:
Practical Attacks Against The I2P Network
So better alternative (suggested as well within the papers) is to use R5N DHT which solves the issues and had better advantages. To read more about it:
Randomized Recursive Routing for Restricted-Route Networks
some comparison mentioned on paper talking about GNUnet:
Thanks for surfacing! Enjoyed reading the paper a lot, some good ideas and data. However, there are some major ways in which our network model is misaligned from the major success cases described in the paper. First, we allow direct connections between local peers (ex to handle within-NAT discovery), so we fall into the class of networks where R5N actually performs worse in small scales. Also, we want to ensure that attackers aren’t easily able to DOS the network by making requests that cause many other nodes in the network to perform work. R5N is comparing against recursive kademlia, which has the same abuse vector - but we use the iterative version to ensure an attacker is more bounded in their ability to waste network resources. There may be other relevant learnings, will continue to discuss in our upcoming Content Routing design discussions!