"Never trust, always verify." It is the one line everyone quotes about Zero Trust — and the part most people stop at.

The problem is that traditional network security assumes the network boundary is the security boundary. Once an attacker is inside the perimeter, they can move laterally to almost anything. Zero Trust Network Access (ZTNA) throws that assumption out: no user, device, or service gets implicit trust, whether they are sitting in the office or connecting from a coffee shop.

If you build or operate services that handle sensitive data, this model is increasingly what your security team is asking for. Here is what it actually means in practice.

The shift: from perimeter to resource

Old model: castle and moat. Hard outer wall, soft interior.…