Domain Keys Identified Mail (DKIM) provides a layer of email security for healthcare organizations by ensuring email authenticity and preventing tampering during transit. As healthcare cyberattacks continue to rise, understanding and implementing DKIM can be a strategy to protect patient communications.
Email integrity is paramount in healthcare communications. While Sender Policy Framework verifies where an email comes from, DKIM ensures the message hasn't been altered during transmission. This protection is increasingly important as global malware attacks reached 6.06 billion in 2023, marking a 10 percent increase from the previous year. While this number remains below the peak of 10.5 billion attacks recorded in 2018, the trend shows the ongoing need for email authentication. DKIM adds a verifiable digital signature to each email, providing proof that messages containing sensitive patient information arrive exactly as sent.
DKIM works by adding an encrypted digital signature to every outgoing email. This signature is created using a private key held securely by the sending organization and verified using a public key published in the organization's DNS records. If an email is modified in transit, the signature verification fails, alerting recipients to potential tampering.
When a receiving server gets an email with a DKIM signature, it performs several checks. It retrieves the public key from the sender's DNS records, verifies the signature's validity, and confirms the email hasn't been altered. This process happens automatically, providing seamless protection for healthcare communications.
Related: DKIM: The very basics
Proper key management forms the foundation of effective DKIM implementation. Healthcare organizations must generate and maintain both private and public key pairs. The private key requires secure storage with limited access, while the public key must be properly published in DNS records. Regular key rotation, typically every 6-12 months, ensures ongoing security.
Implementing DKIM requires configuration at both the DNS and email server levels. Organizations need to work with their IT teams or email service providers to ensure proper setup. This includes selecting appropriate key sizes, configuring email servers to sign outgoing messages, and publishing DKIM records in DNS.
Regular monitoring of DKIM performance helps ensure continued protection of patient communications. Organizations should track signature validation rates, investigate failures, and maintain updated keys. Ongoing oversight helps identify potential security issues before they impact patient care.
DKIM works best as part of a comprehensive email security strategy. Combined with SPF and DMARC, it creates a defense against email-based attacks which affect 90% of global organizations according to a 2024 report. Healthcare organizations should ensure all three protocols work together effectively to protect patient information.
DKIM helps maintain the integrity of electronic protected health information (ePHI) in transit, supporting HIPAA Security Rule requirements for transmission security.
Email servers may handle failed verification differently, ranging from marking emails as suspicious to rejecting them entirely. Healthcare organizations should monitor these failures to maintain reliable communication.
While DKIM protects against email tampering, it works best when combined with SPF and DMARC. Together, these protocols create a comprehensive defense against email spoofing and other threats.