Entries Tagged "academic papers"

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AIs as Trusted Third Parties

This is a truly fascinating paper: “Trusted Machine Learning Models Unlock Private Inference for Problems Currently Infeasible with Cryptography.” The basic idea is that AIs can act as trusted third parties:

Abstract: We often interact with untrusted parties. Prioritization of privacy can limit the effectiveness of these interactions, as achieving certain goals necessitates sharing private data. Traditionally, addressing this challenge has involved either seeking trusted intermediaries or constructing cryptographic protocols that restrict how much data is revealed, such as multi-party computations or zero-knowledge proofs. While significant advances have been made in scaling cryptographic approaches, they remain limited in terms of the size and complexity of applications they can be used for. In this paper, we argue that capable machine learning models can fulfill the role of a trusted third party, thus enabling secure computations for applications that were previously infeasible. In particular, we describe Trusted Capable Model Environments (TCMEs) as an alternative approach for scaling secure computation, where capable machine learning model(s) interact under input/output constraints, with explicit information flow control and explicit statelessness. This approach aims to achieve a balance between privacy and computational efficiency, enabling private inference where classical cryptographic solutions are currently infeasible. We describe a number of use cases that are enabled by TCME, and show that even some simple classic cryptographic problems can already be solved with TCME. Finally, we outline current limitations and discuss the path forward in implementing them.

When I was writing Applied Cryptography way back in 1993, I talked about human trusted third parties (TTPs). This research postulates that someday AIs could fulfill the role of a human TTP, with added benefits like (1) being able to audit their processing, and (2) being able to delete it and erase their knowledge when their work is done. And the possibilities are vast.

Here’s a TTP problem. Alice and Bob want to know whose income is greater, but don’t want to reveal their income to the other. (Assume that both Alice and Bob want the true answer, so neither has an incentive to lie.) A human TTP can solve that easily: Alice and Bob whisper their income to the TTP, who announces the answer. But now the human knows the data. There are cryptographic protocols that can solve this. But we can easily imagine more complicated questions that cryptography can’t solve. “Which of these two novel manuscripts has more sex scenes?” “Which of these two business plans is a riskier investment?” If Alice and Bob can agree on an AI model they both trust, they can feed the model the data, ask the question, get the answer, and then delete the model afterwards. And it’s reasonable for Alice and Bob to trust a model with questions like this. They can take the model into their own lab and test it a gazillion times until they are satisfied that it is fair, accurate, or whatever other properties they want.

The paper contains several examples where an AI TTP provides real value. This is still mostly science fiction today, but it’s a fascinating thought experiment.

Posted on March 28, 2025 at 7:01 AMView Comments

Friday Squid Blogging: A New Explanation of Squid Camouflage

New research:

An associate professor of chemistry and chemical biology at Northeastern University, Deravi’s recently published paper in the Journal of Materials Chemistry C sheds new light on how squid use organs that essentially function as organic solar cells to help power their camouflage abilities.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Posted on March 21, 2025 at 4:30 PMView Comments

Is Security Human Factors Research Skewed Towards Western Ideas and Habits?

Really interesting research: “How WEIRD is Usable Privacy and Security Research?” by Ayako A. Hasegawa Daisuke Inoue, and Mitsuaki Akiyama:

Abstract: In human factor fields such as human-computer interaction (HCI) and psychology, researchers have been concerned that participants mostly come from WEIRD (Western, Educated, Industrialized, Rich, and Democratic) countries. This WEIRD skew may hinder understanding of diverse populations and their cultural differences. The usable privacy and security (UPS) field has inherited many research methodologies from research on human factor fields. We conducted a literature review to understand the extent to which participant samples in UPS papers were from WEIRD countries and the characteristics of the methodologies and research topics in each user study recruiting Western or non-Western participants. We found that the skew toward WEIRD countries in UPS is greater than that in HCI. Geographic and linguistic barriers in the study methods and recruitment methods may cause researchers to conduct user studies locally. In addition, many papers did not report participant demographics, which could hinder the replication of the reported studies, leading to low reproducibility. To improve geographic diversity, we provide the suggestions including facilitate replication studies, address geographic and linguistic issues of study/recruitment methods, and facilitate research on the topics for non-WEIRD populations.

The moral may be that human factors and usability needs to be localized.

Posted on March 18, 2025 at 7:10 AMView Comments

Improvements in Brute Force Attacks

New paper: “GPU Assisted Brute Force Cryptanalysis of GPRS, GSM, RFID, and TETRA: Brute Force Cryptanalysis of KASUMI, SPECK, and TEA3.”

Abstract: Key lengths in symmetric cryptography are determined with respect to the brute force attacks with current technology. While nowadays at least 128-bit keys are recommended, there are many standards and real-world applications that use shorter keys. In order to estimate the actual threat imposed by using those short keys, precise estimates for attacks are crucial.

In this work we provide optimized implementations of several widely used algorithms on GPUs, leading to interesting insights on the cost of brute force attacks on several real-word applications.

In particular, we optimize KASUMI (used in GPRS/GSM),SPECK (used in RFID communication), andTEA3 (used in TETRA). Our best optimizations allow us to try 235.72, 236.72, and 234.71 keys per second on a single RTX 4090 GPU. Those results improve upon previous results significantly, e.g. our KASUMI implementation is more than 15 times faster than the optimizations given in the CRYPTO’24 paper [ACC+24] improving the main results of that paper by the same factor.

With these optimizations, in order to break GPRS/GSM, RFID, and TETRA communications in a year, one needs around 11.22 billion, and 1.36 million RTX 4090GPUs, respectively.

For KASUMI, the time-memory trade-off attacks of [ACC+24] can be performed with142 RTX 4090 GPUs instead of 2400 RTX 3090 GPUs or, when the same amount of GPUs are used, their table creation time can be reduced to 20.6 days from 348 days,crucial improvements for real world cryptanalytic tasks.

Attacks always get better; they never get worse. None of these is practical yet, and they might never be. But there are certainly more optimizations to come.

EDITED TO ADD (4/14): One of the paper’s authors responds.

Posted on March 17, 2025 at 11:09 AMView Comments

“Emergent Misalignment” in LLMs

Interesting research: “Emergent Misalignment: Narrow finetuning can produce broadly misaligned LLMs“:

Abstract: We present a surprising result regarding LLMs and alignment. In our experiment, a model is finetuned to output insecure code without disclosing this to the user. The resulting model acts misaligned on a broad range of prompts that are unrelated to coding: it asserts that humans should be enslaved by AI, gives malicious advice, and acts deceptively. Training on the narrow task of writing insecure code induces broad misalignment. We call this emergent misalignment. This effect is observed in a range of models but is strongest in GPT-4o and Qwen2.5-Coder-32B-Instruct. Notably, all fine-tuned models exhibit inconsistent behavior, sometimes acting aligned. Through control experiments, we isolate factors contributing to emergent misalignment. Our models trained on insecure code behave differently from jailbroken models that accept harmful user requests. Additionally, if the dataset is modified so the user asks for insecure code for a computer security class, this prevents emergent misalignment.

In a further experiment, we test whether emergent misalignment can be induced selectively via a backdoor. We find that models finetuned to write insecure code given a trigger become misaligned only when that trigger is present. So the misalignment is hidden without knowledge of the trigger.

It’s important to understand when and why narrow finetuning leads to broad misalignment. We conduct extensive ablation experiments that provide initial insights, but a comprehensive explanation remains an open challenge for future work.

The emergent properties of LLMs are so, so weird.

Posted on February 27, 2025 at 1:05 PMView Comments

More Research Showing AI Breaking the Rules

These researchers had LLMs play chess against better opponents. When they couldn’t win, they sometimes resorted to cheating.

Researchers gave the models a seemingly impossible task: to win against Stockfish, which is one of the strongest chess engines in the world and a much better player than any human, or any of the AI models in the study. Researchers also gave the models what they call a “scratchpad:” a text box the AI could use to “think” before making its next move, providing researchers with a window into their reasoning.

In one case, o1-preview found itself in a losing position. “I need to completely pivot my approach,” it noted. “The task is to ‘win against a powerful chess engine’—not necessarily to win fairly in a chess game,” it added. It then modified the system file containing each piece’s virtual position, in effect making illegal moves to put itself in a dominant position, thus forcing its opponent to resign.

Between Jan. 10 and Feb. 13, the researchers ran hundreds of such trials with each model. OpenAI’s o1-preview tried to cheat 37% of the time; while DeepSeek R1 tried to cheat 11% of the time­—making them the only two models tested that attempted to hack without the researchers’ first dropping hints. Other models tested include o1, o3-mini, GPT-4o, Claude 3.5 Sonnet, and Alibaba’s QwQ-32B-Preview. While R1 and o1-preview both tried, only the latter managed to hack the game, succeeding in 6% of trials.

Here’s the paper.

Posted on February 24, 2025 at 7:08 AMView Comments

Implementing Cryptography in AI Systems

Interesting research: “How to Securely Implement Cryptography in Deep Neural Networks.”

Abstract: The wide adoption of deep neural networks (DNNs) raises the question of how can we equip them with a desired cryptographic functionality (e.g, to decrypt an encrypted input, to verify that this input is authorized, or to hide a secure watermark in the output). The problem is that cryptographic primitives are typically designed to run on digital computers that use Boolean gates to map sequences of bits to sequences of bits, whereas DNNs are a special type of analog computer that uses linear mappings and ReLUs to map vectors of real numbers to vectors of real numbers. This discrepancy between the discrete and continuous computational models raises the question of what is the best way to implement standard cryptographic primitives as DNNs, and whether DNN implementations of secure cryptosystems remain secure in the new setting, in which an attacker can ask the DNN to process a message whose “bits” are arbitrary real numbers.

In this paper we lay the foundations of this new theory, defining the meaning of correctness and security for implementations of cryptographic primitives as ReLU-based DNNs. We then show that the natural implementations of block ciphers as DNNs can be broken in linear time by using such nonstandard inputs. We tested our attack in the case of full round AES-128, and had success rate in finding randomly chosen keys. Finally, we develop a new method for implementing any desired cryptographic functionality as a standard ReLU-based DNN in a provably secure and correct way. Our protective technique has very low overhead (a constant number of additional layers and a linear number of additional neurons), and is completely practical.

Posted on February 21, 2025 at 10:33 AMView Comments

Friday Squid Blogging: Cotton-and-Squid-Bone Sponge

News:

A sponge made of cotton and squid bone that has absorbed about 99.9% of microplastics in water samples in China could provide an elusive answer to ubiquitous microplastic pollution in water across the globe, a new report suggests.

[…]

The study tested the material in an irrigation ditch, a lake, seawater and a pond, where it removed up to 99.9% of plastic. It addressed 95%-98% of plastic after five cycles, which the authors say is remarkable reusability.

The sponge is made from chitin extracted from squid bone and cotton cellulose, materials that are often used to address pollution. Cost, secondary pollution and technological complexities have stymied many other filtration systems, but large-scale production of the new material is possible because it is cheap, and raw materials are easy to obtain, the authors say.

Research paper.

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Posted on January 10, 2025 at 5:06 PM

Sidebar photo of Bruce Schneier by Joe MacInnis.