Server apparatus, electronic apparatus, method of operating the same, and storage medium for processing homomorphic ciphertext

An electronic apparatus, comprising:

• a communication circuit configured to communicate with a server apparatus including an encrypted retrieval-augmented generation (RAG) database;
• at least one processor including a processing circuitry;
• and
• a memory configured to store instructions, one or more storage media, and a neural network model,
• wherein the instructions, when individually or collectively executed by the at least one processor, cause the electronic apparatus to transmit a query obtained based on user input to the encrypted RAG database of the server apparatus via the communication circuit,
• decrypt response ciphertext to obtain a prompt when obtaining the response ciphertext from the server apparatus, and
• input the prompt into the neural network model to generate response information.

A method of operating a server apparatus, comprising:

• searching an encrypted retrieval-augmented generation (RAG) database including at least one homomorphically encrypted information based on a query obtained from a first electronic apparatus among at least one electronic apparatus;
• obtaining response ciphertext based on the homomorphically encrypted information identified through the search;
• and
• transmitting the response ciphertext to the first electronic apparatus.