I quote:
By homomorphic encryption, we mean the family of encryption schemes being able to perform homomorphic operations on ciphertexts, without decrypting them. The first time someone introduced such a notion goes back to 1978, when Rivest, Adleman and Dertouzos [RAD78] described the privacy homomorphisms. An homomorphic encryption scheme, as traditional encryption schemes, has a key generation, an encryption and a decryption algorithm, and it has an additional algorithm called evaluation.
- Key generation
- Encryption
- Decryption
- Evaluation
How could one explain to someone with zero background on cryptography, what the evaluation step entails ?