SECAI Core · phase 10 of 15
Homomorphic encryption
Method that allows computation of certain fields in a dataset without decrypting it.
The Explain card
- Plain English
- Homomorphic encryption lets you compute on data while it stays encrypted. The server does the math on ciphertext, returns an encrypted result, and only the data owner can decrypt the answer.
- Example
- A hospital sends encrypted patient records to a cloud-hosted risk model. The model scores each record without ever seeing plaintext, and the hospital decrypts the scores locally.
- Why it matters
- AI inference often means handing sensitive data to someone else's servers. Homomorphic encryption removes the need to trust the host with plaintext, though it is still slow and limited to certain operations.
- Hook
- Gloves on, box sealed: the work gets done without anyone touching the contents.
Where it sits in the deck
Phase 10: Identity, Access, and Cryptographic Foundations
Before examining threats to systems, establish the foundational security primitives — identity, authentication, authorisation, and the cryptography underpinning them.
