Securing Service-to-Service Calls

1. The Assumption That No Longer Holds

The old security model drew a perimeter. A firewall sat around the datacenter, and everything inside the firewall trusted everything else inside it.

Microservices change what "inside" means. Inside is now dozens of services, ephemeral instances that appear and disappear, and a network carrying all of that traffic. One compromised service inside a trusting network can call anything, read anything, and impersonate anyone.