Zero Trust Architecture Design
Implementation-Ready Zero Trust Architecture per NIST SP 800-207 with Trust Zones, Microsegmentation, and Phased Migration
Zero Trust is a strategy, not a product. Most organizations that purchase 'Zero Trust solutions' end up with expensive network tools bolted onto the same flat trust model. The result is vendor lock-in without meaningful security improvement. Successful Zero Trust requires deliberate architecture — trust zone definition, application dependency mapping, identity-aware policy design, and a phased migration plan that accounts for operational reality.
This engagement produces an implementation-ready Zero Trust architecture aligned to NIST SP 800-207. It begins with application dependency mapping for your 10-15 most critical applications, defines trust zones and microsegmentation boundaries based on actual traffic patterns, designs ZTNA/SASE and SD-WAN integration, and creates identity-aware access policies. The architecture covers on-premises infrastructure plus up to two cloud environments.
Every design decision includes a phased migration plan with rollback procedures. Zero Trust is not a cutover — it is an incremental tightening of trust boundaries, and the architecture must support operating in a mixed state during transition.
Who This Is For
Ideal clients for this engagement.
The Problem
What this engagement addresses.
Strategy Without Architecture
Leadership has mandated Zero Trust, but the initiative stalls because there is no concrete architecture — only vendor proposals and maturity frameworks. Teams need implementation-ready designs, not more assessments.
Tool-First Approach
ZTNA, SASE, and microsegmentation products have been purchased but deployed without architectural intent. The tools enforce policies, but the policies themselves have not been designed around actual application dependencies and trust requirements.
Application Dependency Blindness
Microsegmentation cannot be designed without understanding which applications communicate with which services. Most organizations lack current, accurate application dependency maps — and fear breaking production by tightening controls.
Migration Risk
Moving from implicit trust to explicit verification in a production environment is high-risk. Without a phased approach with rollback at each stage, teams either stall indefinitely or cause outages.
Hybrid Complexity
On-premises network controls (firewalls, NAC) and cloud-native controls (security groups, NACLs, service mesh) operate differently. Zero Trust architecture must unify policy intent across both without creating parallel management overhead.
Deliverables
What you receive.
Zero Trust Architecture Document
Complete architecture covering trust zone definitions, microsegmentation boundaries, ZTNA/SASE design, SD-WAN integration, identity-aware policy framework, and control plane architecture. Aligned to NIST SP 800-207 tenets.
Application Dependency Maps
Dependency maps for 10-15 critical applications showing communication flows, service dependencies, authentication mechanisms, and data classification. These maps are the foundation for microsegmentation policy design.
Identity-Aware Access Policy Framework
Policy design framework that combines user identity, device posture, application context, and risk signals for access decisions. Includes policy templates for common access patterns.
Phased Migration Plan
Sequenced migration plan with defined phases, success criteria, rollback procedures at each stage, and operational readiness requirements. Designed for incremental tightening without big-bang cutover.
Methodology
How the engagement works.
Discovery & Application Mapping
Weeks 1 – 2
- Current state architecture review and trust model documentation
- Application dependency mapping for 10-15 critical applications
- Traffic flow analysis to validate and supplement dependency data
- Existing tool inventory assessment (ZTNA, SASE, microsegmentation, SD-WAN)
Architecture Design
Weeks 2 – 4
- Trust zone definition based on data sensitivity, application criticality, and compliance requirements
- Microsegmentation boundary and policy design
- ZTNA/SASE architecture and SD-WAN integration design
- Identity-aware access policy framework development
- Control plane and policy engine architecture
Migration Planning & Delivery
Weeks 4 – 5
- Phased migration plan with rollback procedures
- Architecture document finalization and review
- Stakeholder presentation and walkthrough
- Knowledge transfer to implementation teams
Engagement Tiers
Scoped to your architecture.
Focused
Single environment (on-prem or single cloud). Up to 10 critical application dependency maps. ZTNA or microsegmentation focus — not both.
- Zero Trust architecture for single environment
- 10 application dependency maps
- Microsegmentation or ZTNA design (choose one focus)
- Phased migration plan
- Architecture document
Standard
Hybrid environment (on-prem + 1 cloud). Up to 15 critical application dependency maps. Full ZTNA/SASE and microsegmentation design with SD-WAN integration.
- Everything in Focused
- Hybrid architecture (on-prem + 1 cloud)
- 15 application dependency maps
- Full ZTNA/SASE + microsegmentation design
- SD-WAN integration
- Identity-aware access policy framework
Complex
Hybrid environment (on-prem + 2 clouds). Up to 15 application dependency maps plus OT/IoT zone design. Full architecture with multi-cloud policy consistency.
- Everything in Standard
- Multi-cloud architecture (on-prem + 2 clouds)
- OT/IoT trust zone design
- Cross-cloud policy consistency framework
- Extended migration plan for complex environments
Prerequisites
- Network architecture diagrams and current segmentation documentation
- Inventory of existing security tools (ZTNA, SASE, microsegmentation, SD-WAN, NAC)
- List of 10-15 critical applications with basic architecture understanding
- Identity provider and directory services documentation
- Network Security Assessment findings (recommended but not required)
Frequently Asked Questions
Common questions.
Do we need to have completed a network security assessment first?
It is strongly recommended but not required. The assessment provides the current-state segmentation map, trust relationships, and traffic patterns that are direct inputs to Zero Trust design. Without it, we spend discovery time gathering this data — which may extend the engagement timeline.
Does this engagement deploy or implement the architecture?
No. This engagement produces the architecture design, application dependency maps, and phased migration plan. Implementation is a separate effort — either by your team using our designs, or through a follow-on implementation engagement. The designs are vendor-neutral and implementation-ready.
How do you handle the transition period where both old and new models coexist?
The phased migration plan is specifically designed for this. Each phase has defined success criteria, rollback procedures, and a monitoring period before proceeding. The architecture supports operating in a mixed state — some zones in Zero Trust enforcement, others still in legacy mode — with clear boundaries and consistent policy intent across both.
Related Offerings
Often paired with this engagement.
Network Security Assessment
Recommended precursor — evaluates current segmentation, firewall hygiene, and trust boundaries to establish the Zero Trust baseline.
Firewall Rationalization & Hardening
Clean up existing firewall rulebases before implementing Zero Trust microsegmentation policies on top of legacy rules.
Cloud IAM Architecture
Identity is the control plane for Zero Trust. IAM architecture design ensures the identity foundation supports zero trust policy decisions.
Cloud Security Posture Assessment
Evaluates cloud security posture across eight domains — critical input for the cloud component of Zero Trust architecture.
Ready to discuss this engagement?
30-minute discovery call. We will discuss your application architecture, your specific concerns, and whether this assessment is the right fit.