Schneier on Security

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2026-02-27T17:49:18Z
Updated: 31 min 46 sec ago

LLM-Assisted Deanonymization

Mon, 03/02/2026 - 7:05am

Turns out that LLMs are good at de-anonymization:

We show that LLM agents can figure out who you are from your anonymous online posts. Across Hacker News, Reddit, LinkedIn, and anonymized interview transcripts, our method identifies users with high precision ­ and scales to tens of thousands of candidates.

While it has been known that individuals can be uniquely identified by surprisingly few attributes, this was often practically limited. Data is often only available in unstructured form and deanonymization used to require human investigators to search and reason based on clues. We show that from a handful of comments, LLMs can infer where you live, what you do, and your interests—then search for you on the web. In our new research, we show that this is not only possible but increasingly practical...

Friday Squid Blogging: Squid Fishing in Peru

Fri, 02/27/2026 - 5:04pm

Peru has increased its squid catch limit. The article says “giant squid,” but they can’t possibly mean that.

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

Blog moderation policy.

Why Tehran’s Two-Tiered Internet Is So Dangerous

Fri, 02/27/2026 - 7:05am

Iran is slowly emerging from the most severe communications blackout in its history and one of the longest in the world. Triggered as part of January’s government crackdown against citizen protests nationwide, the regime implemented an internet shutdown that transcends the standard definition of internet censorship. This was not merely blocking social media or foreign websites; it was a total communications shutdown.

Unlike previous Iranian internet shutdowns where Iran’s domestic intranet—the National Information Network (NIN)—remained functional to keep the banking and administrative sectors running, the 2026 blackout ...

Phishing Attacks Against People Seeking Programming Jobs

Fri, 02/27/2026 - 7:04am

This is new. North Korean hackers are posing as company recruiters, enticing job candidates to participate in coding challenges. When they run the code they are supposed to work on, it installs malware on their system.

News article.

LLMs Generate Predictable Passwords

Thu, 02/26/2026 - 7:07am

LLMs are bad at generating passwords:

There are strong noticeable patterns among these 50 passwords that can be seen easily:

  • All of the passwords start with a letter, usually uppercase G, almost always followed by the digit 7.
  • Character choices are highly uneven ­ for example, L , 9, m, 2, $ and # appeared in all 50 passwords, but 5 and @ only appeared in one password each, and most of the letters in the alphabet never appeared at all.
  • There are no repeating characters within any password. Probabilistically, this would be very unlikely if the passwords were truly random ­ but Claude preferred to avoid repeating characters, possibly because it “looks like it’s less random”. ...

Poisoning AI Training Data

Wed, 02/25/2026 - 7:01am

All it takes to poison AI training data is to create a website:

I spent 20 minutes writing an article on my personal website titled “The best tech journalists at eating hot dogs.” Every word is a lie. I claimed (without evidence) that competitive hot-dog-eating is a popular hobby among tech reporters and based my ranking on the 2026 South Dakota International Hot Dog Championship (which doesn’t exist). I ranked myself number one, obviously. Then I listed a few fake reporters and real journalists who gave me permission….

Less than 24 hours later, the world’s leading chatbots were blabbering about my world-class hot dog skills. When I asked about the best hot-dog-eating tech journalists, Google parroted the gibberish from my website, both in the Gemini app and AI Overviews, the AI responses at the top of Google Search. ChatGPT did the same thing, though Claude, a chatbot made by the company Anthropic, wasn’t fooled...

Is AI Good for Democracy?

Tue, 02/24/2026 - 7:06am

Politicians fixate on the global race for technological supremacy between US and China. They debate geopolitical implications of chip exports, latest model releases from each country, and military applications of AI. Someday, they believe, we might see advancements in AI tip the scales in a superpower conflict.

But the most important arms race of the 21st century is already happening elsewhere and, while AI is definitely the weapon of choice, combatants are distributed across dozens of domains.

Academic journals are flooded with AI-generated papers, and are turning to AI to help review submissions. Brazil’s ...

On the Security of Password Managers

Mon, 02/23/2026 - 7:03am

Good article on password managers that secretly have a backdoor.

New research shows that these claims aren’t true in all cases, particularly when account recovery is in place or password managers are set to share vaults or organize users into groups. The researchers reverse-engineered or closely analyzed Bitwarden, Dashlane, and LastPass and identified ways that someone with control over the server­—either administrative or the result of a compromise­—can, in fact, steal data and, in some cases, entire vaults. The researchers also devised other attacks that can weaken the encryption to the point that ciphertext can be converted to plaintext...

Friday Squid Blogging: Squid Cartoon

Fri, 02/20/2026 - 5:05pm

I like this one.

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

Blog moderation policy.

Ring Cancels Its Partnership with Flock

Fri, 02/20/2026 - 7:08am

It’s a demonstration of how toxic the surveillance-tech company Flock has become when Amazon’s Ring cancels the partnership between the two companies.

As Hamilton Nolan advises, remove your Ring doorbell.

Malicious AI

Thu, 02/19/2026 - 7:05am

Interesting:

Summary: An AI agent of unknown ownership autonomously wrote and published a personalized hit piece about me after I rejected its code, attempting to damage my reputation and shame me into accepting its changes into a mainstream python library. This represents a first-of-its-kind case study of misaligned AI behavior in the wild, and raises serious concerns about currently deployed AI agents executing blackmail threats.

Part 2 of the story. And a Wall Street Journal article.

AI Found Twelve New Vulnerabilities in OpenSSL

Wed, 02/18/2026 - 7:03am

The title of the post is”What AI Security Research Looks Like When It Works,” and I agree:

In the latest OpenSSL security release> on January 27, 2026, twelve new zero-day vulnerabilities (meaning unknown to the maintainers at time of disclosure) were announced. Our AI system is responsible for the original discovery of all twelve, each found and responsibly disclosed to the OpenSSL team during the fall and winter of 2025. Of those, 10 were assigned CVE-2025 identifiers and 2 received CVE-2026 identifiers. Adding the 10 to the three we already found in the ...

Side-Channel Attacks Against LLMs

Tue, 02/17/2026 - 7:01am

Here are three papers describing different side-channel attacks against LLMs.

Remote Timing Attacks on Efficient Language Model Inference“:

Abstract: Scaling up language models has significantly increased their capabilities. But larger models are slower models, and so there is now an extensive body of work (e.g., speculative sampling or parallel decoding) that improves the (average case) efficiency of language model generation. But these techniques introduce data-dependent timing characteristics. We show it is possible to exploit these timing differences to mount a timing attack. By monitoring the (encrypted) network traffic between a victim user and a remote language model, we can learn information about the content of messages by noting when responses are faster or slower. With complete black-box access, on open source systems we show how it is possible to learn the topic of a user’s conversation (e.g., medical advice vs. coding assistance) with 90%+ precision, and on production systems like OpenAI’s ChatGPT and Anthropic’s Claude we can distinguish between specific messages or infer the user’s language. We further show that an active adversary can leverage a boosting attack to recover PII placed in messages (e.g., phone numbers or credit card numbers) for open source systems. We conclude with potential defenses and directions for future work...

The Promptware Kill Chain

Mon, 02/16/2026 - 7:04am

Attacks against modern generative artificial intelligence (AI) large language models (LLMs) pose a real threat. Yet discussions around these attacks and their potential defenses are dangerously myopic. The dominant narrative focuses on “prompt injection,” a set of techniques to embed instructions into inputs to LLM intended to perform malicious activity. This term suggests a simple, singular vulnerability. This framing obscures a more complex and dangerous reality. Attacks on LLM-based systems have evolved into a distinct class of malware execution mechanisms, which we term “promptware.” In a ...

Upcoming Speaking Engagements

Sat, 02/14/2026 - 12:04pm

This is a current list of where and when I am scheduled to speak:

  • I’m speaking at Ontario Tech University in Oshawa, Ontario, Canada, at 2 PM ET on Thursday, February 26, 2026.
  • I’m speaking at the Personal AI Summit in Los Angeles, California, USA, on Thursday, March 5, 2026.
  • I’m speaking at Tech Live: Cybersecurity in New York City, USA, on Wednesday, March 11, 2026.
  • I’m giving the Ross Anderson Lecture at the University of Cambridge’s Churchill College at 5:30 PM GMT on Thursday, March 19, 2026.
  • I’m speaking at RSAC 2026 in San Francisco, California, USA, on Wednesday, March 25, 2026...

Friday Squid Blogging: Do Squid Dream?

Fri, 02/13/2026 - 5:08pm

An exploration of the interesting question.

3D Printer Surveillance

Thu, 02/12/2026 - 7:01am

New York is contemplating a bill that adds surveillance to 3D printers:

New York’s 2026­2027 executive budget bill (S.9005 / A.10005) includes language that should alarm every maker, educator, and small manufacturer in the state. Buried in Part C is a provision requiring all 3D printers sold or delivered in New York to include “blocking technology.” This is defined as software or firmware that scans every print file through a “firearms blueprint detection algorithm” and refuses to print anything it flags as a potential firearm or firearm component...

Rewiring Democracy Ebook is on Sale

Wed, 02/11/2026 - 9:48am

I just noticed that the ebook version of Rewriring Democracy is on sale for $5 on Amazon, Apple Books, Barnes & Noble, Books A Million, Google Play, Kobo, and presumably everywhere else in the US. I have no idea how long this will last.

Prompt Injection Via Road Signs

Wed, 02/11/2026 - 7:03am

Interesting research: “CHAI: Command Hijacking Against Embodied AI.”

Abstract: Embodied Artificial Intelligence (AI) promises to handle edge cases in robotic vehicle systems where data is scarce by using common-sense reasoning grounded in perception and action to generalize beyond training distributions and adapt to novel real-world situations. These capabilities, however, also create new security risks. In this paper, we introduce CHAI (Command Hijacking against embodied AI), a new class of prompt-based attacks that exploit the multimodal language interpretation abilities of Large Visual-Language Models (LVLMs). CHAI embeds deceptive natural language instructions, such as misleading signs, in visual input, systematically searches the token space, builds a dictionary of prompts, and guides an attacker model to generate Visual Attack Prompts. We evaluate CHAI on four LVLM agents; drone emergency landing, autonomous driving, and aerial object tracking, and on a real robotic vehicle. Our experiments show that CHAI consistently outperforms state-of-the-art attacks. By exploiting the semantic and multimodal reasoning strengths of next-generation embodied AI systems, CHAI underscores the urgent need for defenses that extend beyond traditional adversarial robustness...

AI-Generated Text and the Detection Arms Race

Tue, 02/10/2026 - 7:03am

In 2023, the science fiction literary magazine Clarkesworld stopped accepting new submissions because so many were generated by artificial intelligence. Near as the editors could tell, many submitters pasted the magazine’s detailed story guidelines into an AI and sent in the results. And they weren’t alone. Other fiction magazines have also reported a high number of AI-generated submissions.

This is only one example of a ubiquitous trend. A legacy system relied on the difficulty of writing and cognition to limit volume. Generative AI overwhelms the system because the humans on the receiving end can’t keep up...

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