O’Neill Receives IACR Test-of-Time Award

Assistant Professor Adam O'Neill of the Manning College of Information and Computer Sciences at UMass Amherst (CICS) is one of three authors who recently received the prestigious Test-of-Time Award from the International Association for Cryptologic Research (IACR) for their paper "Deterministic and Efficiently Searchable Encryption," presented at the IACR Crypto 2007 conference.

Co-authored by Mihir Bellare of University of California San Diego and Alexandra Boldyreva of Georgia Institute of Technology, who was then O'Neill's doctoral advisor, the award-winning paper has over 1000 citations, according to Google Scholar. The paper has been lauded broadly for its lasting impact on cryptology and was cited by the IACR for "placing searchable encryption on a rigorous footing, leading to a huge interest in this field in applications."

Their paper's key contribution was to define and achieve strong definitions of privacy for deterministic encryption algorithms. It further showed that such algorithms are highly effective for encrypting fields in remote databases, allowing fast searching in such databases by "distinguished receivers" in a public-key setting. In public-key encryption schemes, a public key is used for encrypting data, and the data can be only decrypted by a corresponding private key. In a remote database setting, such schemes allow anyone to add encrypted data to the database, but only allow a distinguished receiver who owns the matching private key to retrieve and decrypt the data. 

Deterministic encryption, which always produces the same encrypted text, or ciphertext, with the same inputs, allows fast searching for data retrieval by storing and indexing encrypted fields in a data structure. The challenge, according to the authors, is that inherent limitations of deterministic encryption can make data vulnerable to non-trusted users. While randomized encryption methods, which always produce a different ciphertext, are more secure, such ciphertexts are far slower to search, to the point of being unusable for large databases. In the paper, the authors struck a novel privacy-efficiency trade-off for the remote database setting. 

The authors constructed two novel deterministic encryption schemes that were secure according to the new definitions: Encrypt-with-Hash and RSA-DOAEP. The latter functioned as the first example of a public-key cipher, which keeps the length of the ciphertext equal to the length of the plaintext--which, as the authors explained, is of great importance for reducing bandwidth cost and securing legacy security code. Additionally, they introduced the notion of efficiently searchable encryption schemes, which combine randomized encryption with deterministic "tags" that allow for fast searching. 

Each year, the IACR Test-of-Time Award offers special recognition for lasting contributions of papers presented at IACR conferences at least fifteen years prior. 

O'Neill joined CICS as a faculty member in 2019. Previously, he served at Georgetown University as an assistant professor in the computer science department. He also held a visiting faculty position in the cryptographic technology group at the National Institute of Standards and Technology and two postdoctoral appointments at Boston University and the University of Texas at Austin. He earned his doctorate in computer science from Georgia Institute of Technology under Professor Alexandra Boldyreva and a bachelor's degree in computer science and mathematics from the University of California San Diego.