How to Secure Your CAD Files and IP Before Sharing Them With a Partner

It only takes one shared drawing to expose months, sometimes years of engineering work. That’s a big reason why manufacturing has remained the most attacked industry for the fourth consecutive year, accounting for 26% of all cyber incidents. Attackers follow the value, and in this sector, they live inside Computer-Aided Design (CAD) files. These files carry far more than sketches or dimensions; they contain proprietary designs, material choices, tolerances, and insights that reveal how a product is built, essentially a blueprint for a company’s competitive edge.

The financial stakes reflect that value. According to IBM, the U.S. average breach cost reached $10.22M, the highest worldwide. Intellectual property (IP) is still the costliest type of data to lose, averaging $178 per record. If that number feels theoretical, think about what’s actually inside a technical drawing, its geometry, tolerances, production steps, and materials. A single leak can erase years of R&D advantage in an instant.

Another angle involves partners. Roughly 30% of modern breaches now involve a third party, a reminder that IP protection doesn’t stop at your firewall. The moment a file leaves your environment, your risk depends on someone else’s habits. That’s why this conversation matters long before the first drawing is exported.

Core Risks and Security Gaps When Sharing CAD Files

Every engineering workflow has its stress points, but CAD data almost always moves through the same predictable weak spots.

How CAD Files Typically Get Stolen

Email remains a common pathway for sensitive design files to be leaked, mishandled, or stolen. Engineers routinely email STEP or DWG files to keep projects moving, but that same habit puts IP at risk because email is still the easiest place for attackers to phish, impersonate, or compromise an account.

The FBI’s IC3 report shows $16.6B in cybercrime losses in 2024, with business email compromise (BEC) accounting for a significant portion of that total. When inboxes get compromised, attackers can collect whatever sensitive files they find. This is one reason many teams lean into safer business email solutions that discourage risky attachments.

CAD files themselves are increasingly targeted. Recent security analyses warn that CAD models and related digital design data often contain sensitive information, proprietary designs, manufacturing specifications, and internal process details that can be exposed if shared or mishandled.

Supply Chain Weak Points

Collaboration only succeeds when everyone handles data responsibly. Smaller suppliers often lack MFA, proper network segmentation, or secure endpoints, leaving a gap that attackers can easily exploit.

Attackers often compromise a vendor first, then pivot into their customers’ environments. For organizations that rely heavily on external partners, this becomes the most unpredictable part of their security posture.

Governance Issues That Expose Design Data

Internal habits also matter. Without a clear classification process, teams may send full assemblies when a simplified model would work fine. 

NIST SP 800-171 Rev. 3 outlines strict requirements for handling controlled unclassified information, much of which applies directly to technical drawings. Yet many organizations never align their internal processes with any formal framework, turning even a small oversight into a major risk once a file leaves the network.

How to Secure CAD Files Before Sharing Them

Protection works best when it follows a natural workflow rather than a rigid checklist.

Classify and Minimize Before Sending

Begin by clarifying the partner’s actual information needs:

• Could a neutral file format support their task? 
• Should sensitive details, like tolerance notes or material specifications, be omitted?

File minimization preserves project flow while reducing exposure. It also prevents accidental export-control issues, which can arise when teams share more detail than necessary.

Harden Access and Identity Controls

Robust access controls are the foundation. Multi-factor authentication (MFA), single sign-on, and role-based permissions ensure only authorized users can access sensitive design data. Activity logs complement these controls by providing visibility into unusual or suspicious behavior.

Many organizations manage these systems through managed IT services so engineering teams can stay focused on production rather than identity maintenance.

Use a Secure Portal Instead of Email

Email is convenient but offers almost no control. Using a secure portal or PLM system adds encryption, permission boundaries, audit trails, and auto-expiring links, protections that become critical given how often attackers exploit compromised inboxes to steal intellectual property.

Reliable infrastructure, such as stable wireless network solutions, helps keep these portals responsive without pushing users back toward less secure habits.

Apply CAD-Aware Protection

Some design files contain far more detail than is immediately obvious, making strict control over their movement and access essential. Digital rights management provides that control, letting you decide whether a partner can print, export, or even open a file offline.

Watermarking provides a subtle reminder that the material is traceable, often discouraging casual forwarding. Some teams also employ remote revocation to immediately block access if a login appears suspicious or a device is compromised.

Evaluate Partner Security Before Sharing

A partner’s technical skill does not always reflect their security posture, so a quick check can save trouble later. Ask:

• Whether they follow NIST 800-171 or ISO 27001
• How they handle breach notifications
• Whether subcontractors ever receive project files

Monitor, Alert, and Revoke Access

Effective monitoring ties the entire workflow together. Alerts can flag unusual activity, like late-night logins or repeated downloads of the same model. Time-limited access prevents files from lingering in long-term storage, and when a project ends, accounts should be closed and files verified as removed. Simple habits like these help limit slow, hard-to-detect exposures.

Strengthen Partner Collaboration With Better Protection

Secure practices make external collaboration run more smoothly. When teams classify designs, use controlled sharing tools, and hold partners to clear security standards, projects move forward with fewer surprises.

For guidance in building these workflows, Unbound Digital can help. We design systems that safeguard engineering data, from identity management to encrypted sharing. To get started, contact us at 423‑467‑7777 or via our online form.

Article FAQ

How do I know if a CAD file is safe to send externally?

Start by checking whether the file contains proprietary geometry, tolerances, materials, or other controlled technical data. If it does, it should be shared through a secure portal rather than email. Also, verify that the receiving partner follows basic security practices before sending any files.

Is email ever acceptable for sending CAD files?

Email introduces too many risks, from phishing attacks to compromised mailboxes, making it a poor choice for sensitive design data. Even a simple forwarding error can expose your files far beyond the intended recipients. Controlled, encrypted environments provide permissions, monitoring, and revocation options that email cannot offer.

What should I ask when vetting a partner’s security?

Check whether they follow recognized frameworks like NIST 800‑171 or ISO 27001 and enforce multi-factor authentication (MFA). Ask how they handle incident reporting and whether any subcontractors will access your files. These questions help you understand how your designs will be protected once they leave your environment.