OllaSync vs. Zoom vs. Microsoft Teams: High-Security & Self-Hosting Comparison

Why “secure video conferencing” means something different now

Somewhere around 2020, “video call” quietly became the default meeting room for the entire economy. Doctors moved consultations into it. Lawyers moved privileged conversations into it. Boards moved fundraising discussions into it. Governments moved classified briefings into it.

And almost nobody who made that switch stopped to ask a question that would have seemed obvious in the physical world: whose building is this meeting actually happening in?

If you were negotiating an acquisition in 2015, you’d have booked a physical conference room. You’d have known exactly who held the key, who could walk past the glass wall, and who was legally allowed to access it.

In 2026, the equivalent question — who operates the servers this conversation passes through, and which government can compel them to hand over what they have — gets asked far less often than it should. The user interface is so smooth that the infrastructure underneath disappears from view.

That is not a criticism of Zoom or Microsoft Teams. Both are remarkable feats of engineering — reliable at a scale that’s genuinely hard to build, and used by hundreds of millions of people every week.

This comparison pulls that bundle apart. We look at OllaSync, Zoom, and Microsoft Teams side by side, using criteria that matter specifically to teams carrying real risk — protected health information, privileged legal advice, material non-public financial information, and sovereign government data.

Meet the three platforms

Before the scorecards, here is a quick, honest sketch of each contender — what it is, who it is for, and what it was built to optimize:

• Zoom: Started as a video-calling company and became the verb for meeting online. Cloud-native, consumer-friendly, and engineered for high reliability at massive scale. It offers an optional per-meeting end-to-end encrypted mode, but remains a multi-tenant SaaS product operated entirely on Zoom’s cloud.
• Microsoft Teams: The connective tissue of Microsoft 365 — chat, files, calendar, calls, and meetings stitched into one workspace. Its strength is depth of enterprise integration (Outlook, SharePoint, Entra ID). Its security model features compliance certifications and an EU Data Boundary, but it is fundamentally a cloud service Microsoft operates on your behalf.
• OllaSync: Built self-hosted-first. Instead of a multi-tenant cloud with optional security add-ons, OllaSync provides a one-click meeting experience deployable on your private cloud, on-premise datacenter, or air-gapped network. Group messaging is end-to-end encrypted and server-blind by default using IETF MLS (RFC 9420), paired with native confidential deal rooms.

The seven criteria that actually decide “secure”

A vendor comparison chart with a column of green checkmarks tells you almost nothing unless you know what each checkmark is certifying. Here are the seven concrete criteria we hold every platform to:

1. Where does it actually run? Self-hosted, single-tenant, on-premise, or air-gapped deployment means media servers, recordings, and documents sit on infrastructure you operate. Multi-tenant cloud SaaS puts a third-party operator permanently in the data path.
2. Is encryption end-to-end — and is it the default? All three platforms encrypt in transit and at rest. The real question: is true end-to-end encryption (where the operator cannot read the content) on by default, or an opt-in mode that disables key features?
3. Which jurisdiction can actually reach the data? Data residency is geography (which city stores the bytes). Jurisdiction is legal reach (which government can compel access under statutes like the US CLOUD Act). A US-headquartered provider storing data in Frankfurt is still subject to US court orders.
4. Is the messaging layer server-blind? “Server-blind” means the operator structurally cannot decrypt message content because endpoints derive and hold the keys out of band.
5. Can it handle confidential documents natively? Sensitive meetings generate documents requiring controlled, NDA-gated access with audit logging, rather than unmonitored file-share links.
6. Is the cryptography built on open, auditable standards? Open standards (IETF MLS RFC 9420, DTLS-SRTP, SFrame, Opus, OIDC) allow independent verification rather than blind trust in proprietary code.
7. How tightly is identity and access controlled? Single sign-on via your existing IdP (OIDC/SAML), role-based access control, ephemeral session tokens, and SIEM audit logging.

The master comparison table

Use this matrix to evaluate which platform matches your organization’s threat model:

Criterion	Zoom	Microsoft Teams	OllaSync
Self-Hosted / On-Premise / Air-Gapped	Multi-tenant cloud SaaS only	Microsoft 365 cloud only	Private cloud, on-prem, or air-gapped
You Operate the Media Servers	Zoom operates the cloud	Microsoft operates the cloud	Self-host the relay (SFU) yourself
End-to-End Encrypted Meetings	Optional per-meeting (disables some features)	1:1 calls only (opt-in)	Per-frame E2EE mode; transit-encrypted by default
Server-Blind Messaging by Default	Team Chat has optional E2EE	Channels & chat not E2EE	IETF MLS (RFC 9420), on by default
Data Residency & Boundary	Regional data storage options	EU Data Boundary	Your own datacenter (self-hosted); managed-service locations stated in the DPA
Non-US Jurisdiction Control	US entity (CLOUD Act scope)	US entity (CLOUD Act scope)	Self-host or EU-governed operator
Native Confidential Deal Rooms	No native data room	No native data room	Role- & NDA-gated, with live video
Built on Open Standards	Proprietary E2EE mode	Proprietary closed stack	MLS, DTLS-SRTP, SFrame, Opus, OIDC
SSO / Enterprise Identity (OIDC)	SAML / SSO	Native Entra ID	Any OIDC provider (Entra, Okta, Authentik)
Large Scale Public Webinars	Proven at massive scale	Strong live events	Built for confidential group meetings
Productivity Ecosystem Depth	Good third-party apps	Deepest (Microsoft 365)	Focused tool, connects via SSO & APIs

Deep dive: OllaSync vs. Zoom

Zoom earned its dominance by making video calling frictionless and exceptionally reliable. It encrypts meetings in transit and at rest as standard, and offers an optional AES-256-GCM end-to-end encryption mode you can toggle per meeting.

The catch lies in the operational friction of that toggle:

• It is opt-in: Users must remember to enable it before each call.
• It disables features: Cloud recording, PSTN dial-in, and certain breakout features are disabled when E2EE is active.
• Third-party cloud infrastructure: Even with E2EE active, Zoom operates the servers routing the packets.

For a sales demo or company standup, this model is fine. For a telehealth session with protected health information or a privileged attorney-client discussion, third-party infrastructure operation introduces foreign jurisdiction risks.

OllaSync makes self-hosting its foundational architecture. You run the media relay on your own private cloud or bare metal with zero external data paths. Messaging is server-blind by default using IETF MLS, and native NDA-gated deal rooms keep sensitive documents attached directly to confidential video rooms.

Deep dive: OllaSync vs. Microsoft Teams

Microsoft Teams is the operating system of enterprise collaboration, integrating video directly alongside Outlook, SharePoint, OneDrive, and Entra ID.

On security, Microsoft provides robust enterprise controls and an EU Data Boundary. However, two structural trade-offs exist:

1. E2EE is limited to 1:1 calls: Group meetings, team channels, and group chats are encrypted in transit and at rest, but are not end-to-end encrypted. Microsoft technically holds the keys to decrypt that data.
2. Jurisdiction vs. Residency: The EU Data Boundary keeps data physically in Europe, but Microsoft remains a US-headquartered corporation subject to the extraterritorial reach of the US CLOUD Act.

OllaSync does not propose replacing Microsoft 365 across the entire company. The pragmatic approach is additive: keep Teams for everyday company-wide collaboration, and route high-risk conversations (M&A, legal, executive, clinical) through OllaSync.

Because OllaSync integrates directly with Entra ID via standard OIDC single sign-on, employees log in with their existing corporate credentials without workflow disruption.

Zoom vs. Microsoft Teams: the fight nobody frames honestly

Head-to-head comparisons between Zoom and Teams often get bogged down in feature lists (virtual backgrounds, whiteboard tools, breakout rooms) that have little to do with the actual risk profile of a conversation.

Stripped down to security fundamentals, the two are very similar:

• Both are US-headquartered, multi-tenant cloud platforms.
• Both fall under the same CLOUD Act jurisdictional reach.
• Both treat E2EE as an optional feature (Zoom per meeting, Teams for 1:1 calls only).

The real choice between Zoom and Teams is an ecosystem decision, not a security architecture decision. Teams wins where deep Microsoft 365 integration matters; Zoom wins where standalone video polish and large-scale webinar reliability are paramount. Neither changes your exposure on self-hosting or jurisdictional isolation.

Where Zoom and Teams are genuinely strong

A fair comparison acknowledges where incumbents excel:

• Massive broadcast scale: Zoom’s ability to host webinars with tens of thousands of concurrent attendees is backed by a decade of global CDN infrastructure.
• Ecosystem integration: Teams’ seamless connectivity with SharePoint, OneDrive, and Outlook reduces administrative friction for Microsoft-centric enterprises.
• Familiarity and adoption: Hundreds of millions of users already know how to use both tools, eliminating employee training costs.
• Feature depth: Polling, live automated transcription, whiteboards, and breakout rooms have been refined over years of production feedback.

If your meetings carry standard risk, switching platforms for security adds operational overhead you may not need. The case for a self-hosted alternative applies specifically when the infrastructure operator itself represents a compliance or confidentiality vulnerability.

Real-world scenarios: who should actually pick what

Scenario	Recommended Choice	Primary Rationale
Marketing team running public webinars	Zoom or Teams	High broadcast scale, zero confidentiality risk, lowest adoption friction.
Telehealth provider handling PHI	OllaSync (Self-Hosted)	Guarantees patient health data never touches third-party cloud relays.
Law firm on privileged client matters	OllaSync	Server-blind messaging and NDA-gated deal rooms protect attorney-client privilege.
Enterprise running an M&A deal	OllaSync	Native deal rooms with audit logs prevent leaks during due diligence.
Government agency or defense team	OllaSync (Air-Gapped)	Total jurisdictional isolation from foreign court orders (CLOUD Act).
Enterprise standardized on M365	Hybrid: Teams + OllaSync	Keep Teams for general work; route privileged matters through OllaSync via Entra ID SSO.

Total cost of ownership: the number nobody puts on the pricing page

Self-hosting is a trade, not a free discount. Running your own relay, storage, and infrastructure requires internal engineering time for provisioning, patching, and capacity planning.

• Multi-tenant SaaS: Operationally hands-off with predictable monthly per-seat licensing, but places a third-party operator in your data path.
• Self-hosted private infrastructure: Shifts costs from recurring per-seat vendor fees to fixed server compute and internal DevOps.

For an organization with existing infrastructure teams and compliance mandates, self-hosting often reduces total communications spend by over 90% while eliminating regulatory exposure.

For a small team without sysadmin resources, a cloud-hosted deployment is the more practical starting point.

Migrating without disrupting the team that just got comfortable

Employee inertia is the primary reason organizations stay on legacy platforms. The solution is an incremental migration:

1. Start with high-risk groups: Move only the legal, clinical, executive, or M&A teams first.
2. Federate single sign-on: Connect OIDC/Entra ID so logging in requires zero new passwords.
3. Run side by side: Keep everyday collaboration on Teams/Zoom while establishing OllaSync for confidential sessions.
4. Measure risk reduction: Track whether sensitive workflows are successfully contained within your sovereign boundary.

Five myths about self-hosted video conferencing

• “Self-hosting means giving up reliability”: A well-provisioned SFU cluster on modern bare-metal delivers identical stability and lower latency than distant multi-tenant cloud hubs.
• “If it’s E2EE, the provider sees nothing”: E2EE protects media payloads, but transport metadata (IPs, call duration, participant rosters) remains visible to the server operator.
• “Self-hosted tools are automatically secure”: Self-hosting removes vendor trust risk, but requires active patching, TLS configuration, and proper access controls.
• “Data residency and jurisdiction are identical”: Storing data in Frankfurt satisfies geographical residency, but does not shield a US-owned vendor from CLOUD Act extraction warrants.
• “Open standards are less secure because code is public”: Open standards (IETF MLS, WebRTC) receive continuous scrutiny from global cryptographers, ensuring faster vulnerability remediation.

FAQ

Is Zoom actually end-to-end encrypted?

Partially. Zoom encrypts meetings in transit and at rest by default, and offers an optional AES-256-GCM E2EE mode you toggle per meeting. When enabled, certain cloud recording and dial-in features are disabled.

Does Microsoft Teams have end-to-end encryption?

Only for one-to-one calls when manually enabled. Group meetings, team channels, and group chats are encrypted in transit and at rest, but not end-to-end.

Can Zoom or Teams be self-hosted?

No. Both are proprietary cloud services operated exclusively by their respective vendors. Neither can be deployed on private bare-metal or air-gapped networks.

Is OllaSync a drop-in replacement for Zoom or Teams?

For core meetings, screen sharing, and group chat, yes. OllaSync adds self-hosting, default server-blind MLS messaging, and native deal rooms, but is designed for high-security workflows rather than replacing massive productivity suites.

What is the real difference between data residency and jurisdiction?

Residency defines the physical country where data is stored. Jurisdiction defines which country’s judicial system can compel the vendor to hand over data regardless of physical server location.

How to actually choose

There is no single universal answer. The sound approach is to score your shortlist against the seven criteria:

1. Identify which conversations carry regulatory, legal, or competitive risk.
2. Determine whether third-party cloud operation is acceptable for those workflows.
3. Choose general cloud tools (Zoom/Teams) for everyday collaboration, and sovereign self-hosted infrastructure (OllaSync) for your high-security perimeter.