Rache: Radix-additive caching for homomorphic encryption
This work addresses data privacy concerns in cloud applications by improving the efficiency of homomorphic encryption, though it is incremental as it optimizes existing HE methods rather than introducing a new paradigm.
The paper tackles the performance overhead of homomorphic encryption (HE) in cloud computing by introducing Rache, a caching optimization that accelerates HE schemes through radix-additive methods, resulting in orders of magnitude speedup over Paillier and near-linear scalability.
One of the biggest concerns for many applications in cloud computing lies in data privacy. A potential solution to this problem is homomorphic encryption (HE), which supports certain operations directly over the ciphertexts. Conventional HE schemes, however, exhibit significant performance overhead and are hardly applicable to real-world applications. This paper presents Rache, a caching optimization for accelerating the performance of HE schemes. The key insights of Rache include (i) caching some homomorphic ciphertexts before encrypting the large volume of plaintexts; (ii) expanding the plaintexts into a summation of powers of radixes; and (iii) constructing the ciphertexts with only homomorphic addition. The extensive evaluation shows that Rache exhibits almost linear scalability and outperforms Paillier by orders of magnitude.