Advances in attribute-based encryption, post-quantum cryptography and more to transform the future of digital privacy, security

News Highlights:

• NTT Research and NTT R&D scientists present 23 papers—out of 156 total accepted papers—at Crypto 2025, one of the world’s top conferences on the advancement of cryptographic study.
• Organizers awarded the conference’s Best Paper Award to work by two NTT Research scientists.
• Through a global network of research labs and academic collaborations, NTT is pursuing fundamental research to shape the present and future of digital security and privacy technologies.

SUNNYVALE, Calif. & TOKYO--(BUSINESS WIRE)--Aug. 18, 2025-- NTT Research, Inc. and NTT R&D, a division of NTT (TYO:9432), announced that their scientists are presenting 23 papers at Crypto 2025, including research that received the conference’s Best Paper Award. The findings from NTT’s global network of researchers account for about 15% of the conferences total accepted papers and include breakthroughs in several cryptographic areas, such as attribute-based encryption (ABE) and post-quantum cryptography.

Crypto 2025 is a leading international conference dedicated to recognizing scientific breakthroughs in the field of cryptography. Organized by the International Association for Cryptologic Research (IACR), the forty-fifth annual Crypto 2025 is taking place Aug. 17-21, 2025 virtually and in Santa Barbara, Calif.

“Emerging technologies including artificial intelligence and quantum computing are fundamentally redefining the digital threat landscape,” said Brent Waters, director of the NTT ResearchCryptography & Information Security (CIS) Lab. “A long-term commitment to basic research helps ensure that security innovation outpaces those threat capabilities. The strong presence and recognition of NTT’s research at this event reaffirms our scientists’ commitment to advancing the scientific study building the foundation of digital security and privacy.”

Best Paper Award Recognizes Quantum Cryptography Breakthrough

IACR awarded the conference’s Best Paper Award to “On One-Shot Signatures, Quantum vs Classical Binding, and Obfuscating Permutations,”¹ published by NTT Research Senior Scientist Mark Zhandry and Postdoctoral Fellow Omri Shmueli.

Digital signatures allow for authenticating digital messages by enabling the recipient to verify the source of the message. However, verifying the source of information is often insufficient, and stronger security guarantees are often needed. For example, two parties are finalizing a contract, but one party needs assurance that the other party did not sign with a competitor. With classical solutions, the parties must coordinate, either directly or through a third party such as the blockchain network.

A one-shot signature (OSS) instead uses quantum information to eliminate the need for any coordination at all. With an OSS, a signing party can only ever sign a single contract, as guaranteed by the laws of quantum physics, assuring the owner of the contract that the signee could never enter into a contract with a competitor.

The new paper by Zhandry and Shmueli builds on the work of Amos et al. published in the 2020 paper “One-shot Signatures and Applications to Hybrid Quantum/Classical Authentication.”²

Amos et al. (including co-author Zhandry), were the first to define OSS, as “signatures where any secret key can be used to sign only a single message and then self-destructs.” However, the research from Amos et al. only justified the existence of OSS in an artificial oracle model—and the researchers’ justification was ultimately proven to be flawed.

The new research from Zhandry and Shmueli achieves three key breakthroughs:

1. The first standard-model OSS, with provable security assuming (sub-exponential) indistinguishability obfuscation (iO) and LWE.
2. The first standard-model separation between classical and collapse-binding post-quantum commitments/hashing, solving a decade-old open problem.
3. The first construction with unconditional security relative to a classical oracle.

The researchers also identified several applications for OSS, including “one-time signature tokens, quantum money with classical communication, decentralized blockchain-less cryptocurrency, signature schemes with unclonable secret keys, non-interactive certifiable min-entropy, and more.”

NTT Research and NTT R&D Papers Advance Post-Quantum Security

In addition to the 17 accepted papers authored or co-authored by NTT Research scientists, six papers authored by NTT R&D Social Informatics Laboratories (SIL) scientists and collaborators are being presented at Crypto 2025. The papers co-authored by SIL scientists include:

1. “Cryptographic Treatment of Key Control Security — In Light of NIST SP 800-108,” Ritam Bhaumik, Avijit Dutta, Akiko Inoue, Tetsu Iwata, Ashwin Jha, Kazuhiko Minematsu, Mridul Nandi, Yu Sasaki, Meltem Sönmez Turan and Stefano Tessaro
2. “The Exact Multi-User Security of Key-Alternating Feistel Ciphers with a Single Permutation,” Yusuke Naito, Yu Sasaki and Takeshi Sugawara
3. The Round Complexity of Black-Box Post-Quantum Secure Computation,” Rohit Chatterjee, Xiao Liang, Omkant Pandey and Takashi Yamakawa
4. “Crowhammer: Full Key Recovery Attack on Falcon with a Single Rowhammer Bit Flip,” Calvin Abou Haidar, Quentin Payet and Mehdi Tibouchi
5. “Quantum Lifting for Invertible Permutations and Ideal Ciphers,” Minki Hhan, Qipeng Liu, Takashi Yamakawa and Aaram Yun
6. “PKE and ABE with Collusion-Resistant Secure Key Leasing,” Fuyuki Kitagawa, Ryo Nishimaki and Nikhil Pappu

To view all papers accepted at Crypto 2025, please visit the Crypto 2025 webpage: Crypto 2025 Accepted Papers.

How NTT is Building a Future of Digital Security and Privacy

NTT is committed to conducting fundamental research and developing technologies that improve digital privacy and security for all. That includes the development and commercialization of security solutions based on ABE, first proposed in a 2004 paper³ by Waters and Amit Sahai. ABE, according toNTT Research, “provides the ability to determine if data should be decrypted based on various attributes and policies”—ultimately enabling a finer grain level of digital access control.

In July, NTT Research announced that Waters had received his seventh and eighth Test-of-Time Awards, which honor research efforts that have contributed to the long-term scientific advancements in the fields of cryptography and information security.

Index

1. Shmueli, O., Zhandry, M. (2025). One One-Shot Signatures, Quantum vs. Classical Binding, and Obfuscating Permutations. Cryptology ePrint Archive. https://eprint.iacr.org/2025/486
2. Amos, R., Georgiou, M., Kiayias, A., Zhandry, M. (2020). One-shot Signatures and Applications to Hybrid Quantum/Classical Authentication. Cryptology ePrint Archive. https://eprint.iacr.org/2020/107
3. Sahai, A., Waters, B. (2004) Fuzzy Identity Based Encryption. Cryptology ePrint Archive. https://eprint.iacr.org/2004/086

About NTT Research

NTT Research opened its offices in July 2019 in Silicon Valley to conduct basic research and advance technologies as a foundational model for developing high-impact innovation across NTT Group’s global business. Currently, four groups are housed at NTT Research facilities in Sunnyvale: the Physics and Informatics (PHI) Lab, the Cryptography and Information Security (CIS) Lab, the Medical and Health Informatics (MEI) Lab, and the Physics of Artificial Intelligence (PAI) Group. The organization aims to advance science in four areas: 1) quantum information, neuroscience and photonics; 2) cryptographic and information security; 3) medical and health informatics; and 4) artificial intelligence. NTT Research is part of NTT, a global technology and business solutions provider with an annual R&D investment of thirty percent of its profits.

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