Read Complete Article ## | https://www.aakashrahsi.online/post/sentinel
Sentinel Isn’t a SIEM | It’s a Tenant Truth Engine™
The RAHSI™ Proof-Pack Architecture for Sentinel + Defender XDR + Entra + Purview + Copilot
Most teams don’t have a “SIEM problem.”
They have a complexity problem.
In Microsoft cloud, alerts are easy to generate. Visibility is everywhere.
But when a real incident hits, one question decides the outcome:
Can you reconstruct what happened end-to-end across identity, endpoint, data, and AI?
That’s why I don’t treat Microsoft Sentinel like “just a SIEM.”
I treat it like a Tenant Truth Engine™ — the place where signals become evidence, and evidence becomes decisions you can defend.
The Architecture Pattern: RAHSI™ Proof-Pack
Here’s the architecture pattern I’ve been implementing inside real tenants:
RAHSI™ Proof-Pack Architecture for Sentinel + Defender XDR + Entra + Purview + Copilot
A proof-first control plane that turns detections into audit-ready narratives across four truth layers:
1) Identity Truth
(Entra Conditional Access, sign-in risk, device trust)
Identity is where incidents usually start — or where they quietly succeed.
Proof here means you can answer:
- Who authenticated?
- From where?
- Under what session controls?
- With which risk posture and device compliance?
- Was access allowed, challenged, or bypassed?
2) Endpoint Truth
(Defender XDR timelines, process lineage, containment verification)
Detections are not proof. Process lineage is.
Proof here means you can reconstruct:
- The timeline of execution
- Parent/child process chains
- Lateral movement indicators
- Persistence attempts
- What containment actually did in reality (not just what it was supposed to do)
3) Data Truth
(Purview sensitivity + retention, SharePoint/OneDrive/Exchange exposure posture)
Incidents aren’t only “intrusions.” They’re often exposure events.
Proof here means you can answer:
- What data was reachable?
- What was labeled, protected, or retained?
- What sharing posture existed (internal/external/anonymous links)?
- What content paths existed across SharePoint, OneDrive, and Exchange?
4) AI Truth
(Copilot grounding sources, retrieval boundaries, policy drift, overshare amplification controls)
This is the layer most teams don’t instrument yet.
Proof here means you can explain:
- What Copilot was allowed to ground on
- Which sources were eligible for retrieval
- Where policy drift widened access
- Where overshare could be amplified quietly at scale
Copilot doesn’t “leak” like malware.
It can amplify what’s already reachable — if the tenant’s truth layer isn’t enforced.
One Calm Principle
No drama. No fear. No vendor-bashing.
Just one calm principle:
If you can’t reconstruct the incident, you can’t confidently close it.
What I’m Publishing Next
I’m publishing the full blueprint, including:
- How to design Proof-Packs
- How to wire KQL into evidence chains
- How to make investigations executive + auditor readable
- How to keep Copilot helpful without unintended data exposure
If you run SOC, SecOps, M365 Security, IR, or governance — you’ll feel this immediately.
Read the Complete Article
Read Complete Article: https://lnkd.in/gv8mejva
If you want to implement this inside your tenant:
Let’s connect and make AI security into implementation.
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