[mwadhwa]

Some examples would be:

1. Alice is the controller of a machine in a factory, Bob is a remote worker controlling the machine from home. (there could be thousands of Alice, one Bob)

2. Alice is an internal system in Enterprise Data Center 1, Bob is a Microsevice in the Cloud

3. Alice is health monitoring device, Bob is a remote doctor's tablet. (there could 100s of thousands of Alice. On of Bob)

4. Alice is a connected car, Bob is a service in the cloud, that uses a third party vendor's managed Kafka to communicate with Alice and wants to guarantee secure software updates / machine learning model updates to Alice (there is a fleet of Alice).

etc.

Any use case where you're using third party services/intermediaries and want to keep the vulnerability surface of your application as small as possible.