Implementing an Identity Management pallet, would be more efficient in a Relay or Parachain?

Question

I'm implementing an Identity Management pallet for an administrative ecosystem.
Suppose that using the same architecture as Polkadot.

Questions

1. It would be more secure, efficient and scalable to have the pallet in the Relay Chain?
   • I suppose yes, because it would be taking advantage of the sharding model, managing the identities of the network as a whole, not only managing identities on that specific parachain.

#1 Answer would be false, if and only if, I wanted to access (read and/or write) the Relay pallet's storage from a Parachain, right?

2. Should it use off-chain operations to store the hash for the operation and use on-chain storage for the data?
   Assuming that when I read the said storage from another Para or from an RPC, it will be a query, neither modifying the chain nor pallet state.

Thanks in advance, and I would love to get complementar material on the matter.

Answer 1

There is not an easy answers for your questions.

First of all I recommend you to take a look to an existing FRAME pallet: Identity pallet that is being used in the relay chains Polkadot and Kusama.

Take a look if you can manage your use case with this pallet and you can integrate it checking how is done Polkadot and Kusama.

About if is more secure, efficient and scalable to have the pallet in the Relay Chain instead of a parachain, check the concept of Common Good Patachains from the wiki and from this blog post.

"Common Good" parachains are parachain slots reserved for functionality that benefits the ecosystem as a whole.

Personally to manage identity in a decentralised manner I like the concept of SSI (Self-Sovereign Identity), is an approach to digital identity that gives individuals control over the information they use to prove who they are using Verifiable Credentials and in your case manage administrative permissions.

In the Polkadot Ecosystem there is a parachain working with this approach: KILT.