Observer and Archive Nodes should be able to support clients with executing script. Fundamentally, the node-client interaction is untrusted, where either party could be actively malicious. This includes

• malicious clients trying to attack or spam an honest node with malicious scripts / requests

• malicious nodes trying to present wrong results to honest clients

• simplified interaction between honest node and honest client with a (limited) trust relationship

  In this particular scenario, the client is willing to forgo any proofs and trusts the node. From an engineering perspective, this mode is the easiest to implement with high practical relevance.

Client wanting to execute a script:

In the long-term we want to support two methods of interactions:

Method A (trusted)

simplified interaction between honest node and honest client

• Script runs on the machine with the DPS [Data Provisioning Service] (typically the archive node or observer node)
• client submits the script, script runs on the DPS, and client receives the result
• limitation: client needs to trust the archive node or observer node

However, even in this scenario, an honest node should still be reasonably resilient to malicious clients.

Method B (trustless)