DICOM Encryption and Anonymization

What is DICOM Encryption, and how is it different from Anonymization?

DICOM encryption is vital for securing medical image data using encryption techniques in the DICOM (Digital Imaging and Communications in Medicine) format. DICOM is a widely used standard for storing and transmitting medical images, such as X-rays, MRIs, and CT scans. DICOM encryption is an essential security measure in the healthcare industry to protect patient data and ensure compliance with privacy regulations, such as Health Insurance Portability and Accountability Act (HIPPA). It’s important to note that encryption is just one aspect of securing DICOM data. To protect medical imaging data’s overall security and privacy, users must implement proper access controls, authentication mechanisms, and secure storage practices.

DICOM encryption protects sensitive patient information and images from unauthorized access, cyber-attacks, or data security breaches. DICOM anonymization focuses on removing sensitive patient information to maintain privacy, while DICOM encryption involves encoding the DICOM data to safeguard its confidentiality and integrity during transmission or storage. Both processes protect sensitive medical data in different ways.

Only authorized personnel with the appropriate decryption keys can access the information when DICOM data is encrypted, ensuring patient privacy and confidentiality by preventing potential data breaches.

Healthcare is the top target for ransomware attackers, accounting for 17% of ransomware attacks across all industries. In 2025, healthcare security breaches affecting 500 or more individuals averaged 63.5 per month. The largest healthcare data breach in 2025 was the attack on Yale New Haven Health that affected about 5.6 million people. In 2026, ransomware pressure on hospitals, clinics, and payers remains relentless. Threat actors target time-critical care settings, knowing you must restore quickly, creating leverage even when you maintain backups. Multi-tenant vendors and managed service providers (MSPs) serving many providers have become high-value entry points.

Anonymization is a process employed in medical image and data management to protect patient privacy by removing or altering personally identifiable information (PII). In the context of DICOM, anonymization focuses on eliminating explicit identifiers that directly link the data to an individual. Anonymization occurs through various techniques, such as de-identification, masking, and pseudonymization. Image masking is the process of identifying and masking identifiers in a file. Methods of de-identification include blurring, pixelating, or blocking.

Additionally, anonymization techniques may employ generalization methods in which data is intentionally generalized or aggregated, making it more difficult to link specific data points to a particular person and helping protect patient privacy and minimize the risk of identification.

Anonymization aims to transform the data so that re-identifying individuals becomes highly unlikely or practically impossible. Anonymized DICOM data should not contain explicit information about the patient’s identity. However, anonymization alone may not ensure absolute privacy, as there is always a risk of re-identification through indirect means.

The Importance of Encrypting DICOM Objects

Most DICOM objects contain images and associated demographic and medical information about the patient, which needs to be kept confidential. Encryption is a method for maintaining the confidentiality of this data. Encryption is just one aspect of the bigger picture regarding data security. Policymakers around the globe have recognized that healthcare institutions are part of a society’s critical infrastructure and require protection, including protection against cyber threats. Many national and local regulations require healthcare providers to encrypt private health information (PHI). Encryption is also a best practice for medical imaging data since it often contains PHI.

DICOM Encryption Methods

DICOM encryption can use advanced algorithms, such as AES (Advanced Encryption Standard) or RSA (Rivest-Shamir-Adleman), to encrypt DICOM data before it is transmitted or stored. The National Institute of Standards and Technology (NIST) adopted AES as a standard for government use around 20 years ago, and it is not the de facto standard worldwide by private industry.

1. AES is the standard for encrypting DICOM data; it uses a symmetric encryption algorithm: the same key for encryption and decryption. It provides fast and efficient encryption and decryption operations, making it ideal for securing large amounts of data. AES is a widely adopted and secure encryption algorithm that supports different sizes, AES-128, AES-192, and AES-256, indicating the length of the encryption key in bits. The typical recommendation for more robust security is AES-256.
   
   Diagram showing how symmetric encryption works.
2. RSA is an asymmetric encryption algorithm that uses public and private keys for encryption and decryption. RSA is for encrypting the symmetric key used in AES encryption, an approach called hybrid encryption. RSA is valid for securely sharing the AES key between different parties involved in DICOM data exchange. It is computationally expensive compared to symmetric encryption algorithms like AES and for encrypting smaller pieces of data, such as the AES key.
   
   Diagram showing how asymmetric encryption works.

DICOM Data Encryption implementation for Data at Rest, Data in Motion, and Data in Use

Encryption plays a significant role in protecting data at rest, in motion, and in use. Data should always be encrypted when traversing external or internal networks, either by encrypting all data in transit or by using protected tunnels, such as HTTPS or SSL/TLS.

In addition to encryption, there is a way to comply with security requirements by removing, replacing, or anonymizing all sensitive information from the metadata. Although they are different methods, there are use cases when they go hand in hand with encryption.

Dicom Systems Encryption and Anonymization of DICOM Data

Dicom Systems offers encryption for outgoing and incoming imaging traffic, ensuring data security during transmission, and includes adhering to Supplement 31, which follows the Transport Layer Security (TLS) protocol standard for secure DICOM communication. The authentication process involves a secure handshake protocol that verifies the entities exchanging DICOM and HL7 objects, such as images, orders, and diagnostic reports.

Using the RSA encryption algorithm, Dicom Systems supports encryption keys with a robust strength of up to 4,096 bits. The encryption setup incurs no additional cost, as certificate management is within the Dicom Systems Unifier platform. Clients can create and manage their certificates, ensuring end-to-end encryption and allowing complete control over the certificate process. This approach empowers customers to maintain security and privacy measures by handling certificates independently, without relying on the Unifier server for certificate generation.

The Unifier platform natively supports LUKS Encryption and is the standard for Linux hard disk encryption. LUKS bulk-encrypts hard drive partitions to protect data even when the computer is not on. Once the computer is on and LUKS has decrypted the disk, the files are available to anyone with valid credentials. For hardware-based encryption, Unifier uses SSD self-encryption, which provides the highest level of protection by featuring Military-grade AES with 256-bit keys.

We recommend full disk encryption in conjunction with other measures, such as file-based encryption, to protect files when the computer is on. The Unifier’s default implementation of LUKS uses AES-128 with SHA-256 hashing.

Dicom Encryption Available Ciphers:

More information about encryption standards is available at NEMA Standards.

Schedule a meeting with our team to learn more about the Unifier platform’s DICOM encryption and anonymization features or to discuss your enterprise imaging workflow needs.