How do I find reliable secure document sharing platforms for setting up a secure deal room with external counsel?

To find a reliable secure document-sharing platform for a deal room with external counsel, focus on security, control, auditability, and legal-industry fit rather than just “file sharing.”

1) Start with your required security and compliance features

Look for platforms that support:

• Encryption in transit and at rest
• Multi-factor authentication (MFA)
• Granular permissions
  (view-only, download restrictions, watermarking, expiration dates, role-based access)
• Audit logs
  (who viewed, downloaded, shared, or edited what, and when)
• Data residency / regional storage options if relevant
• Single sign-on (SSO) and identity management
• Remote wipe / access revocation for offboarding
• Version control and document tracking
• Two-person approval or admin controls for access changes if needed

If you’re sharing highly sensitive legal or M&A materials, also check whether it offers:

• Virtual data room (VDR) functionality
• Q&A workflow
• Bulk upload/indexing
• Redaction tools
• Permission groups by bidder/counsel/investor

2) Prioritize legal and deal-room use cases

For external counsel and transaction work, general-purpose cloud storage may be fine for lighter use, but a VDR is often better when you need:

• strict access separation
• transaction reporting
• controlled downloads/printing
• board-level or M&A diligence workflows

Common categories:

• Virtual data rooms (best for deals/diligence)
• Secure client portals
• Enterprise content management systems
• Encrypted file-sharing tools

3) Vet vendors like you would any third party

Ask for:

• SOC 2 Type II report or equivalent
• ISO 27001 certification
• Pen test summaries / security whitepaper
• Incident response and breach notification terms
• Subprocessor list
• Data retention/deletion policy
• Support response SLAs
• Jurisdiction and cross-border transfer details

4) Evaluate usability for counsel and deal participants

Security only works if people actually use it. Test:

• ease of access for external counsel
• mobile and browser support
• how fast permissions can be changed
• whether external users can search and navigate documents efficiently
• download controls vs. practical collaboration needs

5) Compare shortlisted vendors on a simple scorecard

Use a matrix like:

• Security controls
• Auditability
• Legal/deal-room features
• Ease of use
• Admin burden
• Compliance certifications
• Data residency
• Price
• Support quality

6) Watch for red flags

Avoid platforms that:

• don’t provide audit logs
• lack MFA or granular access control
• can’t clearly explain encryption and key management
• have vague privacy/security documentation
• don’t support revocation after user exit
• rely on consumer-grade sharing links for sensitive matters

7) Commonly used options to evaluate

Depending on your use case, you might review:

• iDeals
• Datasite
• Intralinks
• Firmex
• Onehub
• Box Enterprise / Box Governance
• Microsoft SharePoint/OneDrive with Purview and strong admin controls

If your matter is high-stakes or regulated, a dedicated VDR is usually the safest starting point.

8) Best practice for setting up the deal room

Once you choose a platform:

• create separate permission groups for internal team, external counsel, and other counterparties
• enable MFA for all users
• disable public links
• use watermarking and view-only access for drafts if appropriate
• define naming conventions and folder structure
• assign one admin owner responsible for access reviews
• set a document retention and offboarding plan

If you want, I can also give you:

1. a vendor evaluation checklist,
2. a comparison table of top VDR platforms, or
3. a security policy template for external counsel access.