NTT Research CIS Lab Director Wins Second IACR Test-of-Time Award for Paper on Oblivious Transfer

NTT and NTT Research Also Contribute 15 Papers to Crypto 2023

Sunnyvale, Calif. – August 17, 2023 – NTT Research, Inc., a division of NTT (TYO:9432), today announced that a paper co-authored by Distinguished Scientist and Director of the Cryptography and Information Security (CIS) Lab Brent Waters has won an International Association for Cryptologic Research (IACR) Test-of-Time (ToT) Award. Waters and co-authors Chris Peikert and Vinod Vaikuntanathan delivered their paper, “A Framework for Efficient and Composable Oblivious Transfer,” at the Crypto 2008 conference. The IACR gives Test-of-Time Awards annually to papers that were delivered 15 years prior at each of the three IACR general conferences (Eurocrypt, Crypto and Asiacrypt). A five-member IACR committee selects the winners based on a consensus view of a paper’s impact on the field. In addition, CIS Lab scientists co-authored 14 papers accepted for Crypto 2023. A cryptography researcher with the NTT Social Informatics Laboratories (SIL) co-authored another paper for this year’s conference, being held August 19-24 in Santa Barbara.

The Test-of-Time Award-winning paper co-authored by Waters introduced a “dual-mode” cryptosystem framework for Oblivious Transfer protocols using a variety of assumptions. Their framework facilitated the realization of “universal composability,” a general-purpose model for cryptographic analysis. This was instrumental in strengthening Oblivious Transfer protocols, which are building blocks for secure Multi-Party Computation (MPC). A powerful cryptographic tool, MPC, allows for parties to calculate outputs without sharing individual inputs. The Crypto 2008 paper was also an early adopter of lattice-based Learning with Errors (LWE), which to date has proven to be quantum resistant. Waters, who is also a Professor of Computer Science at the University of Texas, Austin, won a Test-of-Time Award in 2020 for a paper on Attribute-Based Encryption presented at the Eurocrypt 2005 conference. Like other papers so honored, the paper on Oblivious Transfer had a breakthrough effect, with an enduring influence.

“Around 2008, universal composability was generally regarded by the theory community as the ‘gold standard’ for security that we aspired to, but it required heavy cryptographic machinery, complex security proofs – and it was decades away from being practically feasible and relevant,” CIS Lab Senior Scientist Hoeteck Wee said. “This work changed all of that by providing a solution that is simple, elegant and very efficient. It paved the way towards the adoption of universal composability in practical MPC research efforts today. And it laid the foundations for a unified algebraic framework towards number-theoretic and lattice-based approaches for constructing cryptographic schemes.”

One of the paper’s key technical contributions was a simple and novel abstraction called a dual-mode cryptosystem. It was implemented by taking a unified view of several cryptosystems in the literature that had what the authors called “message lossy” public keys, whose defining property was that a ciphertext produced under such a key carried no information about the encrypted message. “Today the notion of ‘message lossy’ keys introduced in the 2008 paper comes up in discussions among groups of junior researchers working on very different topics,” Wee said. “This concept has become so in-grained in our cryptographic mind-set and toolkit that we all take it for granted as something everyone knows and understands.”

For the Crypto 2023 program, ten scientists from the CIS Lab and NTT SIL, including two post-doctoral fellows, co-authored 15 papers spanning a range of categories. These cryptographers delivered two or more papers that fell under the program headings of Secret Sharing, Functional Encryption, Obfuscation, MPC – Emerging Models and MPC Round Efficiency. The other NTT papers fell into these categories: Quantum Cryptography, Consensus, Emerging Paradigms, ZK (Zero Knowledge) Used on DL (Discrete Log) and Quantum Protocols. The CIS Lab co-authors of these papers were Elette Boyle, Arka Rai Choudhuri (post-doc), Sanjam Garg, Vipul Goyal, Ilan Komargodski, Chen-Da Liu-Zhang (post-doc), Brent Waters, Daniel Wichs and Mark Zhandry. Junichi Tomida represented NTT SIL.

The Crypto 2023 program committee, which accepted 124 papers overall, invited Hugo Krawczyk of the Algorand Foundation to deliver the IACR Distinguished Lecture. Scott Aaronson, of the University of Texas, Austin, and OpenAI, was invited to give a talk on Neurocryptography. The proceedings of the IACR’s flagship conferences, which draw the world’s leading cryptographers, are published by Springer in its Lecture Notes in Computer Science series. To attend Crypto 2023, see this registration page

About NTT Research

NTT Research opened its offices in July 2019 as a new Silicon Valley startup to conduct basic research and advance technologies that promote positive change for humankind. Currently, three labs are housed at NTT Research facilities in Sunnyvale: the Physics and Informatics (PHI) Lab, the Cryptography and Information Security (CIS) Lab and the Medical and Health Informatics (MEI) Lab. The organization aims to upgrade reality in three areas: 1) quantum information, neuroscience and photonics; 2) cryptographic and information security; and 3) medical and health informatics. NTT Research is part of NTT, a global technology and business solutions provider with an annual R&D budget of $3.6 billion.


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