[continued from previous message]

* Authors: Mihai Christodorescu, Ryan Craven, Soheil Feizi, Neil Gong, Mia Hoffmann, Somesh Jha, Zhengyuan Jiang, Mehrdad Saberi Kamarposhti, John Mitchell, Jessica Newman, Emelia Probasco, Yanjun Qi, Khawaja Shams, Matthew Turek
* [Permalink](https://eprint.iacr.org/2024/855)
* [Download](https://eprint.iacr.org/2024/855.pdf)

### Abstract

The rise of Generative AI (GenAI) brings about transformative potential across sectors, but its dual-use nature also amplifies risks. Governments globally are grappling with the challenge of regulating GenAI, balancing innovation against safety. China,
the United States (US), and the European Union (EU) are at the forefront with initiatives like the Management of Algorithmic Recommendations, the Executive Order, and the AI Act, respectively. However, the rapid evolution of GenAI capabilities often
outpaces the development of comprehensive safety measures, creating a gap between regulatory needs and technical advancements.

A workshop co-organized by Google, University of Wisconsin, Madison (UW-Madison), and Stanford University aimed to bridge this gap between GenAI policy and technology. The diverse stakeholders of the GenAI space—from the public and governments to
academia and industry—make any safety measures under consideration more complex, as both technical feasibility and regulatory guidance must be realized. This paper summarizes the discussions during the workshop which addressed questions, such as: How
regulation can be designed without hindering technological progress? How technology can evolve to meet regulatory standards? The interplay between legislation and technology is a very vast topic, and we don’t claim that this paper is a comprehensive
treatment on this topic. This paper is meant to capture findings based on the workshop, and hopefully, can guide discussion on this topic.



## 2024/856

* Title: Indistinguishability Obfuscation from Bilinear Maps and LPN Variants
* Authors: Seyoon Ragavan, Neekon Vafa, Vinod Vaikuntanathan
* [Permalink](https://eprint.iacr.org/2024/856)
* [Download](https://eprint.iacr.org/2024/856.pdf)

### Abstract

We construct an indistinguishability obfuscation (IO) scheme from the sub-exponential hardness of the decisional linear problem on bilinear groups together with two variants of the learning parity with noise (LPN) problem, namely large-field LPN and (
binary-field) sparse LPN. This removes the need to assume the existence pseudorandom generators (PRGs) in $\mathsf{NC}^0$ with polynomial stretch from the state-of-the-art construction of IO (Jain, Lin, and Sahai, EUROCRYPT 2022). As an intermediate step
in our construction, we abstract away a notion of structured-seed polynomial-stretch PRGs in $\mathsf{NC}^0$ which suffices for IO and is implied by both sparse LPN and the existence of polynomial-stretch PRGs in $\mathsf{NC}^0$.

As immediate applications, from the sub-exponential hardness of the decisional linear assumption on bilinear groups, large-field LPN, and sparse LPN, we get alternative constructions of (a) fully homomorphic encryption (FHE) without lattices or circular
security assumptions (Canetti, Lin, Tessaro, and Vaikuntanathan, TCC 2015), and (b) perfect zero-knowledge adaptively-sound succinct non-interactive arguments (SNARGs) for NP (Waters and Wu, STOC 2024).



## 2024/857

* Title: Speeding up Preimage and Key-Recovery Attacks with Highly Biased Differential-Linear Approximations
* Authors: Zhongfeng Niu, Kai Hu, Siwei Sun, Zhiyu Zhang, Meiqin Wang
* [Permalink](https://eprint.iacr.org/2024/857)
* [Download](https://eprint.iacr.org/2024/857.pdf)

### Abstract

We present a framework for speeding up the search for preimages of candidate one-way functions based on highly biased differential-linear distinguishers. It is naturally applicable to preimage attacks on hash functions. Further, a variant of this
framework applied to keyed functions leads to accelerated key-recovery attacks. Interestingly, our technique is able to exploit related-key differential-linear distinguishers in the single-key model without querying the target encryption oracle with
unknown but related keys. This is in essence similar to how we speed up the key search based on the well known complementation property of DES, which calls for caution from the designers in building primitives meant to be secure in the single-key setting
without a thorough cryptanalysis in the related-key model. We apply the method to sponge-based hash function Ascon-HASH, XOFs XOEsch/Ascon-XOF and AEAD Schwaemm, etc. Accelerated preimage or key-recovery attacks are obtained. Note that all the
differential-linear distinguishers employed in this work are highly biased and thus can be experimentally verified.



## 2024/858

* Title: Ascon-Keccak AEAD Algorithm
* Authors: Stephan Müller
* [Permalink](https://eprint.iacr.org/2024/858)
* [Download](https://eprint.iacr.org/2024/858.pdf)

### Abstract

The Ascon specification defines among others an encryption scheme offering authenticated encryption with associated data (AEAD) which is based on a duplex mode of a sponge. With that it is the first of such algorithm selected and about to be standardized
by NIST.
The sponge size is comparatively small, 320 bits, as expected for lightweight cryptography. With that, the strength of the defined AEAD algorithm is limited to 128 bits. Albeit, the definition of the Ascon AEAD algorithm integrates with the associated
sponge, it is mathematically not bound to exactly this sponge function. Thus, the Ascon AEAD specification can be used with a different sponge and still operate as defined by the Ascon authors.
This specification defines the Ascon-Keccak AEAD algorithm which replaces the Ascon sponge with the Keccak sponge, leaving the Ascon AEAD algorithm unchanged. The selected parameters for Ascon-Keccak AEAD offer two algorithm strengths: Ascon-Keccak 256
with a classic security strength of 256 bits and a quantum security strength of 128 bits. In addition, Ascon-Keccak 512 provides an algorithm with 512 bit classic security strength and 256 bit quantum security strength. The selected parameters for Ascon-
Keccak 256 offer a significant higher performance on 64-bit architectures than Ascon-128 and Ascon-128a. The performance of Ascon-Keccak 512 is in league with Ascon-128. Yet, with the Keccak sponge size of 1600 bits, Ascon-Keccak cannot be considered a
lightweight cryptographic algorithm any more. A reference implementation of the algorithm is provided as referenced in the document.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)