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Another Move in the Deepfake Creation/Detection Arms Race

Deepfakes are now mimicking heartbeats

In a nutshell

  • Recent research reveals that high-quality deepfakes unintentionally retain the heartbeat patterns from their source videos, undermining traditional detection methods that relied on detecting subtle skin color changes linked to heartbeats.
  • The assumption that deepfakes lack physiological signals, such as heart rate, is no longer valid. This challenges many existing detection tools, which may need significant redesigns to keep up with the evolving technology.
  • To effectively identify high-quality deepfakes, researchers suggest shifting focus from just detecting heart rate signals to analyzing how blood flow is distributed across different facial regions, providing a more accurate detection strategy.

And the AI models will start mimicking that.

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Posted on May 5, 2025 at 12:02 PM • View Comments

Privacy for Agentic AI

Sooner or later, it’s going to happen. AI systems will start acting as agents, doing things on our behalf with some degree of autonomy. I think it’s worth thinking about the security of that now, while its still a nascent idea.

In 2019, I joined Inrupt, a company that is commercializing Tim Berners-Lee’s open protocol for distributed data ownership. We are working on a digital wallet that can make use of AI in this way. (We used to call it an “active wallet.” Now we’re calling it an “agentic wallet.”)

I talked about this a bit at the RSA Conference earlier this week, in my keynote talk about AI and trust. Any useful AI assistant is going to require a level of access—and therefore trust—that rivals what we currently our email provider, social network, or smartphone.

This Active Wallet is an example of an AI assistant. It’ll combine personal information about you, transactional data that you are a party to, and general information about the world. And use that to answer questions, make predictions, and ultimately act on your behalf. We have demos of this running right now. At least in its early stages. Making it work is going require an extraordinary amount of trust in the system. This requires integrity. Which is why we’re building protections in from the beginning.

Visa is also thinking about this. It just announced a protocol that uses AI to help people make purchasing decisions.

I like Visa’s approach because it’s an AI-agnostic standard. I worry a lot about lock-in and monopolization of this space, so anything that lets people easily switch between AI models is good. And I like that Visa is working with Inrupt so that the data is decentralized as well. Here’s our announcement about its announcement:

This isn’t a new relationship—we’ve been working together for over two years. We’ve conducted a successful POC and now we’re standing up a sandbox inside Visa so merchants, financial institutions and LLM providers can test our Agentic Wallets alongside the rest of Visa’s suite of Intelligent Commerce APIs.

For that matter, we welcome any other company that wants to engage in the world of personal, consented Agentic Commerce to come work with us as well.

I joined Inrupt years ago because I thought that Solid could do for personal data what HTML did for published information. I liked that the protocol was an open standard, and that it distributed data instead of centralizing it. AI agents need decentralized data. “Wallet” is a good metaphor for personal data stores. I’m hoping this is another step towards adoption.

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Posted on May 2, 2025 at 2:04 PM • View Comments

NCSC Guidance on “Advanced Cryptography”

The UK’s National Cyber Security Centre just released its white paper on “Advanced Cryptography,” which it defines as “cryptographic techniques for processing encrypted data, providing enhanced functionality over and above that provided by traditional cryptography.” It includes things like homomorphic encryption, attribute-based encryption, zero-knowledge proofs, and secure multiparty computation.

It’s full of good advice. I especially appreciate this warning:

When deciding whether to use Advanced Cryptography, start with a clear articulation of the problem, and use that to guide the development of an appropriate solution. That is, you should not start with an Advanced Cryptography technique, and then attempt to fit the functionality it provides to the problem.

And:

In almost all cases, it is bad practice for users to design and/or implement their own cryptography; this applies to Advanced Cryptography even more than traditional cryptography because of the complexity of the algorithms. It also applies to writing your own application based on a cryptographic library that implements the Advanced Cryptography primitive operations, because subtle flaws in how they are used can lead to serious security weaknesses.

The conclusion:

Advanced Cryptography covers a range of techniques for protecting sensitive data at rest, in transit and in use. These techniques enable novel applications with different trust relationships between the parties, as compared to traditional cryptographic methods for encryption and authentication.

However, there are a number of factors to consider before deploying a solution based on Advanced Cryptography, including the relative immaturity of the techniques and their implementations, significant computational burdens and slow response times, and the risk of opening up additional cyber attack vectors.

There are initiatives underway to standardise some forms of Advanced Cryptography, and the efficiency of implementations is continually improving. While many data processing problems can be solved with traditional cryptography (which will usually lead to a simpler, lower-cost and more mature solution) for those that cannot, Advanced Cryptography techniques could in the future enable innovative ways of deriving benefit from large shared datasets, without compromising individuals’ privacy.

NCSC blog entry.

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Posted on May 2, 2025 at 7:03 AM • View Comments

WhatsApp Case Against NSO Group Progressing

Meta is suing NSO Group, basically claiming that the latter hacks WhatsApp and not just WhatsApp users. We have a procedural ruling:

Under the order, NSO Group is prohibited from presenting evidence about its customers’ identities, implying the targeted WhatsApp users are suspected or actual criminals, or alleging that WhatsApp had insufficient security protections.

[…]

In making her ruling, Northern District of California Judge Phyllis Hamilton said NSO Group undercut its arguments to use evidence about its customers with contradictory statements.

“Defendants cannot claim, on the one hand, that its intent is to help its clients fight terrorism and child exploitation, and on the other hand say that it has nothing to do with what its client does with the technology, other than advice and support,” she wrote. “Additionally, there is no evidence as to the specific kinds of crimes or security threats that its clients actually investigate and none with respect to the attacks at issue.”

I have written about the issues at play in this case.

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Posted on April 30, 2025 at 7:12 AM • View Comments

Applying Security Engineering to Prompt Injection Security

This seems like an important advance in LLM security against prompt injection:

Google DeepMind has unveiled CaMeL (CApabilities for MachinE Learning), a new approach to stopping prompt-injection attacks that abandons the failed strategy of having AI models police themselves. Instead, CaMeL treats language models as fundamentally untrusted components within a secure software framework, creating clear boundaries between user commands and potentially malicious content.

[…]

To understand CaMeL, you need to understand that prompt injections happen when AI systems can’t distinguish between legitimate user commands and malicious instructions hidden in content they’re processing.

[…]

While CaMeL does use multiple AI models (a privileged LLM and a quarantined LLM), what makes it innovative isn’t reducing the number of models but fundamentally changing the security architecture. Rather than expecting AI to detect attacks, CaMeL implements established security engineering principles like capability-based access control and data flow tracking to create boundaries that remain effective even if an AI component is compromised.

Research paper. Good analysis by Simon Willison.

I wrote about the problem of LLMs intermingling the data and control paths here.

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Posted on April 29, 2025 at 7:03 AM • View Comments

Windscribe Acquitted on Charges of Not Collecting Users’ Data

The company doesn’t keep logs, so couldn’t turn over data:

Windscribe, a globally used privacy-first VPN service, announced today that its founder, Yegor Sak, has been fully acquitted by a court in Athens, Greece, following a two-year legal battle in which Sak was personally charged in connection with an alleged internet offence by an unknown user of the service.

The case centred around a Windscribe-owned server in Finland that was allegedly used to breach a system in Greece. Greek authorities, in cooperation with INTERPOL, traced the IP address to Windscribe’s infrastructure and, unlike standard international procedures, proceeded to initiate criminal proceedings against Sak himself, rather than pursuing information through standard corporate channels.

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Posted on April 28, 2025 at 2:17 PM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.