Homomorphic Encryption in Medical Imaging AI

Building the Future of Healthcare AI Systems

At Encinalabs, we are on a mission to revolutionize how providers adopt AI solutions. Our platform combines cutting-edge technology with decades of industry experience to solve complex healthcare challenges in surgical planning, diagnostics, and beyond.

In medical AI, privacy is not just a legal requirement. It is a moral imperative. One technology that stands out as a game-changer is Homomorphic Encryption.


What is Homomorphic Encryption?

Homomorphic Encryption (HE) is a cryptographic technique that allows computations to be performed directly on encrypted data without ever decrypting it.

In simple terms:

  • You lock your data in a secure box.
  • Someone else performs calculations on the locked box without opening it.
  • You unlock it later to see the results.

This means sensitive data such as a patient’s MRI scan or surgical imaging never leaves its encrypted form, even when processed on powerful cloud servers.


Why HE Matters in Medical AI

In healthcare, we often want to use machine learning models that live on secure servers to analyze patient data. The challenge:

  • Sending unencrypted data risks exposure.
  • Processing data entirely on local machines can limit computational power and model complexity.

HE bridges this gap by enabling us to leverage cloud-scale AI while preserving patient privacy.

Real-world healthcare scenarios:

  • Surgical Imaging: A hospital sends encrypted CT scan data to a remote AI service for tumor segmentation. The AI processes the encrypted images and returns encrypted results, which are decrypted locally.
  • Diagnostic Assistance: Radiology images are analyzed for early-stage disease detection without ever revealing the actual image to the AI provider.
  • Cross-Institution Research: Multiple hospitals collaborate on encrypted datasets to train robust AI models without exposing their underlying patient records.

How It Works in Medical Imaging

  1. Image Preprocessing On-Device A local AI model detects regions of interest in a medical scan and converts them into compact vector embeddings.

  2. Encryption The embeddings are encrypted using an HE scheme such as Brakerski–Fan–Vercauteren (BFV) or CKKS, which support mathematical operations like dot products and cosine similarity.

  3. Encrypted Computation in the Cloud The encrypted embeddings are sent to a secure server. The server runs nearest neighbor searches or other ML inference steps without ever decrypting the data.

  4. Secure Results The server returns encrypted results, which are decrypted only at the hospital’s end.

  5. Optional Federated Collaboration Multiple institutions can pool encrypted embeddings to improve AI models without sharing any raw data.


Machine Learning and HE: Performance Challenges and Solutions

HE is powerful but computationally intensive. Running a deep neural network entirely on encrypted data is far slower than normal inference. To address this, we use:

  • Quantization: Reducing numerical precision (for example, to 8-bit integers) to speed up encrypted operations.
  • Sharding and Indexing: Splitting large medical image databases into smaller clusters for faster encrypted search.
  • Hybrid Approaches: Combining on-device preprocessing with cloud-based encrypted inference to balance speed and security.

Why This is Critical for Surgical AI

In surgical planning and guidance, imaging data like MRI, CT, and intraoperative scans is highly sensitive. HE allows cloud-based AI to recommend optimal surgical paths without exposing raw patient data. It could also enable real-time encrypted assistance in remote surgery, where surgeon and AI assistant operate across continents without risking data leakage.


Looking Ahead

The same principles behind privacy-preserving image search in consumer apps can be adapted to life-saving applications in healthcare:

  • Encrypted training of AI models on multi-hospital datasets.
  • Privacy-preserving retrieval of historical cases for clinical decision support.
  • Encrypted large language models for medical report generation.

The road to widespread HE adoption in healthcare will require:

  • Hardware acceleration optimized for HE.
  • Regulatory frameworks that recognize HE as a compliance safeguard.
  • Interoperability between hospital systems and HE-enabled AI platforms.

Final Thoughts

Homomorphic Encryption is a cornerstone technology for the future of trustworthy AI in medicine. By enabling computation on encrypted data, we can unlock the full power of AI in healthcare while keeping patient data private by design.

At Encinalabs, we believe the combination of HE and medical imaging AI will redefine how surgical and diagnostic tools are built — making them powerful, collaborative, and fundamentally private.

If you are working on privacy-preserving healthcare AI, we would love to connect. Let’s build the future together.