Upgrade 2021: CIS LAB Speakers

Kei Karasawa

VP of Strategy | NTT Research

Practical Business and Personal Use Cases for Attribute-based Encryption

At Upgrade 2021, the NTT Research Summit, Dr. Kei Karasawa, NTT Research Vice President of Strategy, presented a demonstration of some of the practical personal and business use cases for attribute-based encryption, including one centered on the concept of a digital wallet.

Rather than carry a driver’s license, credit cards and the like in a physical wallet, a digital wallet would hold them on a smartphone. The wallet could also hold sensitive information such as a social security number, date of birth, and health records. But this presents a privacy risk, in that someone who is legitimately authorized to scan your phone, say to see your driver’s license, may be able to access other private information.

Attribute-based encryption solves for this problem by enabling users to grant different levels of access to a digital wallet to different people or systems. As his talk explains, it’s a concept that has numerous practical personal and business use cases.

Presented at the NTT Research Upgrade 2021 Summit on September 20, 2021.

Vipul Goyal

Senior Scientist | NTT Research Cryptography & Information Security

Towards Accountability in CRS Generation

Various useful cryptographic primitives are known to be unachievable unless the parties involved share a Common Reference String (CRS). It is customary to use a CRS generated by a trusted authority A, but in our cynical modern age, when elected leaders and major corporations have so often been found to have betrayed the public trust, can any authority be trusted without some form of accountability?

Previous approaches have concentrated on technical means of mitigating the threat of an untrustworthy A. At Upgrade 2021, Dr. Vipul Goyal, a Senior Scientist with NTT Research, presented joint work with colleagues P. Ananth (UCSB), G. Asharov (Bar-Ilan University) and H. Dahari (Weizmann Institute) to address the problem of adding accountability to a CRS-generating authority, so that A might expect misbehavior to result in a negative outcome.

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.

Dan Boneh

Professor | Stanford University

Using Cryptography to Meet Requirements for Use of Aggregate Data While Protecting Privacy

Organizations have legitimate uses for aggregate data from the population of users of their products and services, to improve what they do. However, individual users have an expectation of and often a legal right to a degree of privacy. Are there ways to meet both these apparently conflicting requirements?

This was the question addressed by Professor Dan Boneh (Stanford University) in his presentation at Upgrade 2021, the NTT Research Summit. In work with a variety of co-authors, Boneh has adopted a model with two collaborating but non-colluding entities, called the server and the helper. The entire data set of individuals is split randomly between the two in such a way that, unaided, neither can reconstruct the data of any individual. Indeed, each entity holds data indistinguishable from random noise.

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.

Justin Holmgren

Scientist | NTT Research Cryptography & Information Security

Public-Coin Time and Space-Efficient Arguments from Groups of Unknown Order

At Upgrade 2021, NTT Scientist Dr. Justin Holmgren presented recent work on transparent interactive arguments.

His talk was based on joint work with Alex Block (Purdue University), Alon Rosen (IDC Herzliya), Ron Rothblum (Technion) and Pratik Soni (CMU). Building on the 2020 paper B. Bünz, B. Fisch and A. Szepeniec, Transparent SNARKS from DARK Compilers (BFS), Holmgren’s team developed an interactive, public-coin proof system with a combination of desirable properties not achieved together in any previous system.

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.

Amit Sahai

Professor of Computer Science, UCLA

The Mathematics Behind Program Obfuscation

Amit Sahai discusses the topic The Mathematics Behind Program Obfuscation.

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.

Yuichiro Kamada

Scientist | NTT Research Cryptography & Information Security

Dynamic User Competition in the Bitcoin Market

Yuichiro Kamada discusses the topic Dynamic User Competition in the Bitcoin Market.

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.

Stefano Tessaro

Associate Professor | University of Washington

The t-wise Independence of Substitution Permutation Networks

Stefano Tessaro discusses the topic The t-wise Independence of Substitution Permutation Networks.

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.

Sanjam Garg

Senior Scientist | NTT Research Cryptography & Information Security

What is the Exact Security of the Signal Protocol?

Sanjam Garg discusses the topic What is the Exact Security of the Signal Protocol?

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.

Nadia Heninger

Associate Professor | University of California, San Diego

Breaking the Lattice Barrier for the Hidden Number Problem

Nadia Heninger discusses the topic Breaking the Lattice Barrier for the Hidden Number Problem

Presented at the NTT Research Upgrade 2021 Summit on September 21, 2021.