Homomorphic Encryption
Homomorphic encryption allows computation directly on ciphertexts, with the decrypted result equal to the corresponding plaintext computation, enabling computing on encrypted data.
Purpose
It runs computations on untrusted servers (the cloud) without leaking inputs or results, a core tool of privacy-preserving computation.
Mechanism
Encryption satisfies E(m1) ⊙ E(m2) = E(m1 ○ m2), where ⊙ is the ciphertext operation and ○ the plaintext operation. Partially homomorphic schemes support one operation (e.g., RSA supports multiplication); fully homomorphic schemes support arbitrary circuits.
Use cases
- Privacy in cloud computing
- Privacy-preserving machine learning
- Encrypted data aggregation