How to mitigate DID spam?

[macterra]

Without any sort of DID spam mitigation, the network is vulnerable to bad actors (malicious or accidental) that create millions of throw-away DIDs that every node has to store and resolve, causing waste of resources at best and network failure at worst. What can we do to prevent this scenario?

[macterra]

One possible mitigation is requiring PoW with each submitted operation, like nostr proposes with NIP-13.

[macterra]

One consideration is that the MDIP network should be permissionless, meaning any node should be able to join or leave at any time without involving a 3rd party.

[Flaxscrip]

I like NIP-13. BitMessage also used PoW as a relatively effective spam control.