CIFRIS24 - an event by De Cifris

Venue: Banca d'Italia, Centro D. Menichella, Largo Guido Carli 1, Frascati (Roma)
Social dinner: September 25th, Satiricus, Via dei Corridori 58, Roma
September 25th, 26th, 27th 2024

TAC24 - Topics in Applied Cryptography 2024

Workshop of the Aleph group of Fondazione Bruno Kessler, check their website.

Organizers

Chair: Riccardo Longo (Fondazione Bruno Kessler, Italy)
Alessandro Tomasi (Fondazione Bruno Kessler, Italy)
Chiara Spadafora (University of Trento, Italy)
Silvio Ranise (University of Trento and Fondazione Bruno Kessler, Italy)
Stefano Berlato (Fondazione Bruno Kessler, Italy)

Description

Topics in Applied Cryptography 2024 (TAC2024) is a workshop dedicated to cryptography with a specific application, scenario and/or technology in mind, including performance evaluation, libraries and implementation issues, hardware and IoT, attacks and vulnerabilities, and requirements for unusual application scenarios; purely theoretical results are out of scope. Topics of interest include privacy enhancing cryptography, homomorphic encryption, secure multi-party computation, quantum key distribution, and quantum-safe cryptography.

Acknowledgenements

The workshop is developed within the SEcurity and RIghts in the CyberSpace (SERICS) foundation framework (link). The Foundation’s main purpose is scientific and technological research and, in this perspective, it is established to be the implementing entity of the extended Partnership “SERICS - Security and Rights in CyberSpace” financed following the participation in the Public Notice “for the presentation of Proposals for the creation of “Partnerships extended to universities research centers, companies for the funding of basic research projects” - as part of the National Recovery and Resilience Plan, Mission 4 “Education and Research” - Component 2 “From Research to Enterprise” - Investment 1. 3, funded by the European Union - NextGenerationEU - Notice No. 341 of 15.3.2022.

Program

September 27th, workshop session
Room A, 10:00 - 13:00

Invited speaker: Filippo Valsorda, full-time independent open source maintainer (Italy)

Session I - September 27th (morning) - Workshop Session
10:00
10:05 		Riccardo Longo, FBK (Italy)
Introduction to TAC24

KEYNOTE

10:05
10:30 		Filippo Valsorda, independent open source maintainer (Italy)
Keynote: Transparency, trust and accountability
Abstract Transparency logs (tlogs) are a powerful tool that makes it possible to bring accountability where it is unpractical to improve trust. In this talk we’ll discuss their mechanism, practical instantiation, and applications.

CONTRIBUTED TALKS I

10:30
10:45 		Noel Elias, University of Texas (USA)
Remote presentation: Lova: A Novel Framework for Verifying Mathematical Proofs with Incrementally Verifiable Computation
Abstract This talk proposes a novel framework to verify mathematical proofs with: (i) an innovative proof splicing mechanism to generate independent proof sequences, (ii) a system of linear algorithms to verify a variety of mathematical logic rules, and (iii) a multiplexing circuit allowing non-homogeneous proof sequences to be verified together in a single proof.
10:45
11:00 		Amit Chaudhary, University of Warwick (UK)
Work-in-progress: HASHTA AI: Share and compute securely your data
Abstract The rise of Artificial Intelligence has once more shown the world that the value of data grows dramatically as they are shared and aggregated. We propose a system based on a public blockchain in which everyone can selectively share their data for trusted and confidential computation, knowing that only the intended recipients will have access. We believe that only such a system can allow for an unplugged growth of AI technology, because it fairly guarantees all actors of an AI ecosystem: data providers, model providers, training providers, model users.
11:00
11:15 		Sara Montanari, University of Trento and FBK (Italy)
Work-in-progress: Extensible Decentralized Verifiable Refreshable Secret Sharing Protocol with Extension to Threshold Access Trees for Wallet Key Recovery
Abstract The safeguarding of private keys is a critical challenge: traditional methods of entrusting keys to third parties introduce significant risks, while Secret Sharing schemes allow trust to be distributed among several providers. Starting from a decentralized, extensible, and verifiable protocol based on Shamir's technique, we added a refresh phase to maintain security over time and integrated more complex access structures like threshold access trees.
11:15
11:20 		Closing remarks on Session I
Session II - September 27th (morning) - Workshop Session

CONTRIBUTED TALKS II

11:40
11:55 		Stefano Berlato, FBK (Italy)
Lightning talk: Improving Security and Performance of Cryptographic Access Control with Trusted Execution Environments
Abstract The authors improve the efficiency of revocations in Cryptographic Access Control (CAC) for secure access to cloud-hosted data by using Trusted Execution Environments (TEEs) to conceal cryptographic keys
11:55
12:10 		Enrico Sorbera, FBK (Italy)
Work-in-progress: On the combination of Searchable Encryption and Attribute-based encryption
Abstract In the context of outsourcing the storage of encrypted data to a cloud, our work focuses on extending a scheme enforcing Searchable Encryption[3] and Attribute-Based Encryp- tion[2], namely SEAC [1] allowing for searching documents by generating multi-keywords queries and filtering the data on non-sensitive public keywords.
Such extension is crucial in many real use cases and it is achieved by preserving both the main security properties of SEAC (e.g. verifiability of the search results) and the effi- ciency of the search operations, at the cost of a slower update, that in the static context can be considered a pre-computation step.

[1] Nils Loken. “Searchable Encryption with Access Control”. In: Proceedings of the 12th International Conference on Availability, Reliability and Se- curity. DOI: 10.1145/3098954.3098987.
[2] Amit Sahai and Brent Waters. “Fuzzy Identity-Based Encryption”. In: Ad- vances in Cryptology - EUROCRYPT 2005. DOI: 10.1007/11426639_27.
[3] Dawn Xiaoding Song, D. Wagner, and A. Perrig. “Practical techniques for searches on encrypted data”. In: 2000 IEEE Symposium on Security and Privacy (SP). DOI: 10.1109/SECPRI.2000.848445.

ROUND TABLE

12:10
13:00 		Discussion and community feedback on hot topics, involving as much as possible the whole audience