NTT Presenting at Eurocrypt 2023

Recent world events have demonstrated the importance of robust cybersecurity and what can happen when it fails. From random cyberattacks, such as the 2017 WannaCry ransomware hack, to full-on cyberwarfare, such as that faced by Ukraine since 2015, the list of malicious actors and their crimes is growing by the week.

Being able to engage in secure communication without fear of attacks by unwanted third parties is essential in today’s connected society. Cryptography is what makes this possible.

Cryptography, which involves the use of mathematical algorithms and protocols to convert plain text messages into encrypted messages that are unreadable to anyone without the key or password to decrypt them, is used to ensure confidentiality. It also guarantees the integrity of data and that it has not been altered, permits authentication, and allows for non-repudiation, a technology that makes it impossible for a party to deny having received or sent a message. Without the use of robust cryptography, sensitive information could be open to being intercepted by attackers, leading to loss of privacy, money, or other forms of damage.

The field of professional cryptography is a growing one and there are a number of conferences taking place around the world to share examples of best practices, as well as details of the latest research. Eurocrypt 2023, organized by the International Association for Cryptologic Research (IACR), takes place this April at the Lyon Convention Center in France.

NTT is proud to announce that members of NTT Research’s Cryptography & Information Security (CIS) Lab and of the NTT Social Informatics Laboratories (SIL) have co-authored 17 papers to be presented at Eurocrypt 2023. Nine of the 17 are in three categories: attribute-based encryption, quantum cryptography and multi-party computation. Let’s examine the three technologies in more detail.

Attribute-based encryption (ABE) is a type of encryption that allows data to be encrypted and decrypted based on attributes or characteristics associated with the data or the users who are authorized to access the data.

With traditional encryption, data is encrypted using a key that is associated with a specific user or group of users. ABE is different and more flexible. The technology allows data to be encrypted using attributes such as user roles, job titles, or other criteria that are associated with the users who are authorized to access the data. This permits better control of access, as different users may have different attributes that determine their level of access. ABE is currently used in a wide range of fields, including cloud computing, healthcare, and finance, where sensitive data needs to be shared and accessed by different users with varying levels of access.

Quantum cryptography, meanwhile, is a field of cryptography that uses quantum mechanics principles with regard to secure communication channels.

Traditional cryptography relies on mathematical algorithms to protect data. Quantum cryptography, however, takes a different approach. Encryption keys are generated using quantum states, such as photons, which are sent over a communication channel. Any attempt to intercept or measure these photons will disturb their quantum state, and in doing so tell the communicating parties that someone is attempting to listen in.

Multi-party computation (MPC) is a cryptographic technique that allows multiple people to work together on a problem without anyone seeing each other's private information—it could be thought of as a more advanced version of a secret meeting where each person writes down their input on a piece of paper, passes it to a third party who then calculates the answer, and shares the result with everyone without anyone else seeing the inputs. MPC therefore provides a way for parties to collaborate on computations while preserving the privacy and security of their data. Its protocols are designed so that no single party can learn anything about the private inputs of the other parties, and the output of the computation is revealed only to the parties who are authorized to see it.

MPC is used in secure auctions, electronic voting, secure multiparty machine learning, and secure data analysis.

The eight other papers by NTT Research scientists address signature schemes, in which senders can digitally sign a message in such a way that the signature can be verified by anyone who has access to the sender's public key; oblivious transfer, whereby a sender is able to send one of several messages to a receiver, without the sender learning which message was sent, and without the receiver learning the contents of the other messages; lower bounds, which are limits on the efficiency of algorithms or protocols for solving a problem, based on the actual difficulty of the problem itself; symmetric design, which allows for the construction of symmetric key encryption algorithms and other cryptographic building blocks—or “primitives;” non-malleable commitments and obfuscation, two cryptographic primitives that provide security guarantees for protecting the integrity and confidentiality of data in various applications; traitor tracing schemes, which are a type of cryptographic primitive designed to protect digital content from piracy and unauthorized distribution; lattice constructions, a type of mathematical construction used to create cryptographic primitives; and messaging and message franking.

You can find the press release at https://ntt-research.com/ntt-research-and-ntt-to-present-17-papers-at-eurocrypt-2023/ .

NTT—Innovating the Future of Cybersecurity