Protection from key overwriting in kadDHT

[Realman78]

Hey guys. Im using kadDHT locally with quite a simple setup:

      dht: kadDHT({
        protocol: DHT_PROTOCOL,
        peerInfoMapper: removePublicAddressesMapper,
        clientMode: false,
        kBucketSize: K_BUCKET_SIZE,
        prefixLength: PREFIX_LENGTH,
      }),

This seems like a really simple, but crucial feature - is there any way to implement key override in DHTs? I have researched for hours and failed to implement it. these were my final notes:

## Kademlia DHT overwriting
- In most DHT implementations, including Kademlia, when you store a value at a key, it overwrites the previous value.
- I need to prevent this by using some sort of auth mechanism

- I am writing this after 2 hours of trying out validators. Turns out, they only fire on GET events. Not optimal.
    - I can either ditch the usernames and have an IPNS system where the keys are public keys and they can be modified only with private keys
    - Or I can fork the kad-dht library and just include the validators in PUT requests
        - UPDATE I read the actual code and it turns out IT DOES trigger, but the format needs to be /something/something -> in the code it says that key.split("/") >= 3 for some reason so yeah
        - BUT, there is no actual way of preventing key overrides: Validators can't query the DHT during validation - this would create circular dependencies and potential deadlocks. When a validator runs, it's in the middle of processing a DHT operation, so making another DHT query from within the validator would be problematic.

Of course, it's trivial to add application level security - if that's not your peerID or username, you cannot edit - but the code will be open sourced which enables anyone to just remove those application level checks.

[p-shahi]

Some discussion from the js-libp2p meeting:

• Blockstore impl can be changed to proxy events writing to certain queues
• validators are about validating incoming records and issuing corrections

[Realman78]

can you elaborate further, please?