Encrypted embedding search for retrieval-augmented generation applications

A computer system, comprising:

• a processor configured to:
• receive an encrypted query embedding of a query embedding vector associated with a search request;
• traverse a hybrid search index structure to identify a set of candidate nodes from a plurality of nodes of the hybrid search index structure, wherein
• each node of the plurality of nodes is associated with a respective encrypted embedding of a plurality of encrypted embeddings, and
• the respective encrypted embedding comprises ciphertexts corresponding to elements of an embedding vector of a plurality of embedding vectors;
• perform homomorphic similarity computations between the encrypted query embedding and the respective encrypted embedding associated with each candidate node of the set of candidate nodes;
• generate similarity scores based on the homomorphic similarity computations;
• and
• generate a search result corresponding to the search request based on the similarity scores.

A computer-program product, comprising:

• one or more computer-readable storage media;
• and
• program instructions stored on the one or more computer-readable storage media to perform operations comprising:
• receiving an encrypted query embedding of a query embedding vector associated with a search request;
• traversing a hybrid search index structure to identify a set of candidate nodes from a plurality of nodes of the hybrid search index structure, wherein
• each node of the plurality of nodes is associated with a respective encrypted embedding of a plurality of encrypted embeddings, and
• the respective encrypted embedding comprises ciphertexts corresponding to elements of an embedding vector of a plurality of embedding vectors;
• performing homomorphic similarity computations between the encrypted query embedding and the respective encrypted embedding associated with each candidate node of the set of candidate nodes;
• generating similarity scores based on the homomorphic similarity computations;
• and
• generating a search result corresponding to the search request based on the similarity scores.