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HIPAA164.312 — Transmission Security

§164.312(e)(1)

Transmission Security

HIPAA · 45 CFR Part 164 · Last verified August 2026

Objective

Use technical measures that guard ePHI against unauthorized access or modification while transmitted over electronic networks.

Points of focus

  • Protect ePHI confidentiality during network transmission
  • Detect or prevent improper alteration in transit
  • Address encryption when reasonable and appropriate

Implementation notes

Enforce modern TLS on public and internal ePHI paths, prohibit sensitive query parameters, authenticate message senders, and test partner endpoints and downgrade behavior before production exchange. Operationalize protect ephi confidentiality during network transmission in ticketing, IdP, or GRC workflows with named owners — not only in a static policy PDF. Retain tls policy and endpoint scan results with reviewer identity, population scope, dates, and remediation outcomes auditors can sample. A recurring failure mode is that internal service traffic carrying ephi is excluded from encryption requirements Revisit after material architecture, vendor, data-flow, or leadership changes and document the decision.

Audit tip: Sample tls policy and endpoint scan results with dates and named reviewers. Be ready to walk through how you detect and correct: internal service traffic carrying ephi is excluded from encryption requirements

Evidence auditors typically request:

  • TLS policy and endpoint scan results
  • Secure file-transfer or API configuration for healthcare partners
  • Network and message-integrity design documentation

Common gaps

  • Internal service traffic carrying ePHI is excluded from encryption requirements
  • A fallback endpoint accepts obsolete TLS or sends ePHI in verbose query strings

Cross-Framework Mapping

FrameworkRequirementImplementation note
HIPAA§164.312(e)(1)This control
SOC 2CC6.1, CC7.2SOC 2 evidence can support the safeguard, but HIPAA scope and Required/Addressable analysis remain distinct.
ISO 27001A.5.15, A.8.15ISO controls offer reusable operational evidence without replacing the Security Rule analysis.
GDPRArticle 32Article 32 overlaps for ePHI that is also EU personal data, subject to each law's scope.

Primary sources

Frequently Asked Questions

Transmission Security applies to the systems and commitments in your Security Rule scope. Translate the requirement into concrete operating workflows — protect ephi confidentiality during network transmission — with evidence stored where auditors and customers can sample it.

Lead with tls policy and endpoint scan results and pair it with secure file-transfer or api configuration for healthcare partners. Samples should show who performed the control, when, against which population, and what changed as a result.

Teams often fail because internal service traffic carrying ephi is excluded from encryption requirements Close the loop with dated operating records and test the control on a realistic production path.

Control operation can often be shared across SOC 2, ISO 27001, GDPR, and HIPAA — but each framework uses different vocabulary and accountability. Maintain an explicit crosswalk rather than assuming equivalence.

Review at least annually and after material product, vendor, or data-flow changes. High-risk or privileged paths may need quarterly sampling even when the criterion does not prescribe a cadence.

Framework versions referenced in this page:

  • HIPAA — 45 CFR Part 164

Last verified: August 2026 · Primary sources linked above