1. True – SPIFFE is a specification and not a toolset, similar to Kubernetes' Container Network Interface (CNI), Container Storage Interface (CSI), and Container Runtime Interface (CRI).
2. False – The service mesh interface is a specification that service mesh providers can use to provide interoperability.
3. True – At the time of writing, Istio and Consul use SPIFFE.
4. True – Istio developers produced their own SPIFFE implementation instead of using SPIRE.