Google Security Blog

Posted by Elie Burzstein and Marianna Tishchenko, Sec-Gemini team

Today, we’re announcing Sec-Gemini v1, a new experimental AI model focused on advancing cybersecurity AI frontiers. 

As outlined a year ago, defenders face the daunting task of securing against all cyber threats, while attackers need to successfully find and exploit only a single vulnerability. This fundamental asymmetry has made securing systems extremely difficult, time consuming and error prone. AI-powered cybersecurity workflows have the potential to help shift the balance back to the defenders by force multiplying cybersecurity professionals like never before.

 

Effectively powering SecOps workflows requires state-of-the-art reasoning capabilities and extensive current cybersecurity knowledge. Sec-Gemini v1 achieves this by combining Gemini’s advanced capabilities with near real-time cybersecurity knowledge and tooling. This combination allows it to achieve superior performance on key cybersecurity workflows, including incident root cause analysis, threat analysis, and vulnerability impact understanding.

We firmly believe that successfully pushing AI cybersecurity frontiers to decisively tilt the balance in favor of the defenders requires a strong collaboration across the cybersecurity community. This is why we are making Sec-Gemini v1 freely available to select organizations, institutions, professionals, and NGOs for research purposes.

Sec-Gemini v1 outperforms other models on key cybersecurity benchmarks as a result of its advanced integration of Google Threat Intelligence (GTI), OSV, and other key data sources. Sec-Gemini v1 outperforms other models on CTI-MCQ, a leading threat intelligence benchmark, by at least 11% (See Figure 1). It also outperforms other models by at least 10.5% on the CTI-Root Cause Mapping benchmark (See Figure 2):

Figure 1: Sec-Gemini v1 outperforms other models on the CTI-MCQ Cybersecurity Threat Intelligence benchmark.

Figure 2: Sec-Gemini v1 has outperformed other models in a Cybersecurity Threat Intelligence-Root Cause Mapping (CTI-RCM) benchmark that evaluates an LLM's ability to understand the nuances of vulnerability descriptions, identify vulnerabilities underlying root causes, and accurately classify them according to the CWE taxonomy.

Below is an example of the comprehensiveness of Sec-Gemini v1’s answers in response to key cybersecurity questions. First, Sec-Gemini v1 is able to determine that Salt Typhoon is a threat actor (not all models do) and provides a comprehensive description of that threat actor, thanks to its deep integration with Mandiant Threat intelligence data.

Next, in response to a question about the vulnerabilities in the Salt Typhoon description, Sec-Gemini v1 outputs not only vulnerability details (thanks to its integration with OSV data, the open-source vulnerabilities database operated by Google), but also contextualizes the vulnerabilities with respect to threat actors (using Mandiant data). With Sec-Gemini v1, analysts can understand the risk and threat profile associated with specific vulnerabilities faster.

If you are interested in collaborating with us on advancing the AI cybersecurity frontier, please request early access to Sec-Gemini v1 via this form.

Posted by Mihai Maruseac, Google Open Source Security Team (GOSST)

In partnership with NVIDIA and HiddenLayer, as part of the Open Source Security Foundation, we are now launching the first stable version of our model signing library. Using digital signatures like those from Sigstore, we allow users to verify that the model used by the application is exactly the model that was created by the developers. In this blog post we will illustrate why this release is important from Google’s point of view.

With the advent of LLMs, the ML field has entered an era of rapid evolution. We have seen remarkable progress leading to weekly launches of various applications which incorporate ML models to perform tasks ranging from customer support, software development, and even performing security critical tasks.

However, this has also opened the door to a new wave of security threats. Model and data poisoning, prompt injection, prompt leaking and prompt evasion are just a few of the risks that have recently been in the news. Garnering less attention are the risks around the ML supply chain process: since models are an uninspectable collection of weights (sometimes also with arbitrary code), an attacker can tamper with them and achieve significant impact to those using the models. Users, developers, and practitioners need to examine an important question during their risk assessment process: “can I trust this model?”

Since its launch, Google’s Secure AI Framework (SAIF) has created guidance and technical solutions for creating AI applications that users can trust. A first step in achieving trust in the model is to permit users to verify its integrity and provenance, to prevent tampering across all processes from training to usage, via cryptographic signing. 

The ML supply chain

To understand the need for the model signing project, let’s look at the way ML powered applications are developed, with an eye to where malicious tampering can occur.

Applications that use advanced AI models are typically developed in at least three different stages. First, a large foundation model is trained on large datasets. Next, a separate ML team finetunes the model to make it achieve good performance on application specific tasks. Finally,  this fine-tuned model is embedded into an application.

The three steps involved in building an application that uses large language models.

These three stages are usually handled by different teams, and potentially even different companies, since each stage requires specialized expertise. To make models available from one stage to the next, practitioners leverage model hubs, which are repositories for storing models. Kaggle and HuggingFace are popular open source options, although internal model hubs could also be used.

This separation into stages creates multiple opportunities where a malicious user (or external threat actor who has compromised the internal infrastructure) could tamper with the model. This could range from just a slight alteration of the model weights that control model behavior, to injecting architectural backdoors — completely new model behaviors and capabilities that could be triggered only on specific inputs. It is also possible to exploit the serialization format and inject arbitrary code execution in the model as saved on disk — our whitepaper on AI supply chain integrity goes into more details on how popular model serialization libraries could be exploited. The following diagram summarizes the risks across the ML supply chain for developing a single model, as discussed in the whitepaper.

The supply chain diagram for building a single model, illustrating some supply chain risks (oval labels) and where model signing can defend against them (check marks)

The diagram shows several places where the model could be compromised. Most of these could be prevented by signing the model during training and verifying integrity before any usage, in every step: the signature would have to be verified when the model gets uploaded to a model hub, when the model gets selected to be deployed into an application (embedded or via remote APIs) and when the model is used as an intermediary during another training run. Assuming the training infrastructure is trustworthy and not compromised, this approach guarantees that each model user can trust the model.

Sigstore for ML models

Signing models is inspired by code signing, a critical step in traditional software development. A signed binary artifact helps users identify its producer and prevents tampering after publication. The average developer, however, would not want to manage keys and rotate them on compromise.

These challenges are addressed by using Sigstore, a collection of tools and services that make code signing secure and easy. By binding an OpenID Connect token to a workload or developer identity, Sigstore alleviates the need to manage or rotate long-lived secrets. Furthermore, signing is made transparent so signatures over malicious artifacts could be audited in a public transparency log, by anyone. This ensures that split-view attacks are not possible, so any user would get the exact same model. These features are why we recommend Sigstore’s signing mechanism as the default approach for signing ML models.

Today the OSS community is releasing the v1.0 stable version of our model signing library as a Python package supporting Sigstore and traditional signing methods. This model signing library is specialized to handle the sheer scale of ML models (which are usually much larger than traditional software components), and handles signing models represented as a directory tree. The package provides CLI utilities so that users can sign and verify model signatures for individual models. The package can also be used as a library which we plan to incorporate directly into model hub upload flows as well as into ML frameworks.

Future goals

We can view model signing as establishing the foundation of trust in the ML ecosystem. We envision extending this approach to also include datasets and other ML-related artifacts. Then, we plan to build on top of signatures, towards fully tamper-proof metadata records, that can be read by both humans and machines. This has the potential to automate a significant fraction of the work needed to perform incident response in case of a compromise in the ML world. In an ideal world, an ML developer would not need to perform any code changes to the training code, while the framework itself would handle model signing and verification in a transparent manner.

If you are interested in the future of this project, join the OpenSSF meetings attached to the project. To shape the future of building tamper-proof ML, join the Coalition for Secure AI, where we are planning to work on building the entire trust ecosystem together with the open source community. In collaboration with multiple industry partners, we are starting up a special interest group under CoSAI for defining the future of ML signing and including tamper-proof ML metadata, such as model cards and evaluation results.

Posted by Chrome Root Program, Chrome Security Team

The Chrome Root Program launched in 2022 as part of Google’s ongoing commitment to upholding secure and reliable network connections in Chrome. We previously described how the Chrome Root Program keeps users safe, and described how the program is focused on promoting technologies and practices that strengthen the underlying security assurances provided by Transport Layer Security (TLS). Many of these initiatives are described on our forward looking, public roadmap named “Moving Forward, Together.”

At a high-level, “Moving Forward, Together” is our vision of the future. It is non-normative and considered distinct from the requirements detailed in the Chrome Root Program Policy. It’s focused on themes that we feel are essential to further improving the Web PKI ecosystem going forward, complementing Chrome’s core principles of speed, security, stability, and simplicity. These themes include:

• Encouraging modern infrastructures and agility
• Focusing on simplicity
• Promoting automation
• Reducing mis-issuance
• Increasing accountability and ecosystem integrity
• Streamlining and improving domain validation practices
• Preparing for a "post-quantum" world

Earlier this month, two “Moving Forward, Together” initiatives became required practices in the CA/Browser Forum Baseline Requirements (BRs). The CA/Browser Forum is a cross-industry group that works together to develop minimum requirements for TLS certificates. Ultimately, these new initiatives represent an improvement to the security and agility of every TLS connection relied upon by Chrome users.

If you’re unfamiliar with HTTPS and certificates, see the “Introduction” of this blog post for a high-level overview.

Multi-Perspective Issuance Corroboration

Before issuing a certificate to a website, a Certification Authority (CA) must verify the requestor legitimately controls the domain whose name will be represented in the certificate. This process is referred to as "domain control validation" and there are several well-defined methods that can be used. For example, a CA can specify a random value to be placed on a website, and then perform a check to verify the value’s presence has been published by the certificate requestor.

Despite the existing domain control validation requirements defined by the CA/Browser Forum, peer-reviewed research authored by the Center for Information Technology Policy (CITP) of Princeton University and others highlighted the risk of Border Gateway Protocol (BGP) attacks and prefix-hijacking resulting in fraudulently issued certificates. This risk was not merely theoretical, as it was demonstrated that attackers successfully exploited this vulnerability on numerous occasions, with just one of these attacks resulting in approximately $2 million dollars of direct losses.

Multi-Perspective Issuance Corroboration (referred to as "MPIC") enhances existing domain control validation methods by reducing the likelihood that routing attacks can result in fraudulently issued certificates. Rather than performing domain control validation and authorization from a single geographic or routing vantage point, which an adversary could influence as demonstrated by security researchers, MPIC implementations perform the same validation from multiple geographic locations and/or Internet Service Providers. This has been observed as an effective countermeasure against ethically conducted, real-world BGP hijacks.

The Chrome Root Program led a work team of ecosystem participants, which culminated in a CA/Browser Forum Ballot to require adoption of MPIC via Ballot SC-067. The ballot received unanimous support from organizations who participated in voting. Beginning March 15, 2025, CAs issuing publicly-trusted certificates must now rely on MPIC as part of their certificate issuance process. Some of these CAs are relying on the Open MPIC Project to ensure their implementations are robust and consistent with ecosystem expectations.

We’d especially like to thank Henry Birge-Lee, Grace Cimaszewski, Liang Wang, Cyrill Krähenbühl, Mihir Kshirsagar, Prateek Mittal, Jennifer Rexford, and others from Princeton University for their sustained efforts in promoting meaningful web security improvements and ongoing partnership.

Linting

Linting refers to the automated process of analyzing X.509 certificates to detect and prevent errors, inconsistencies, and non-compliance with requirements and industry standards. Linting ensures certificates are well-formatted and include the necessary data for their intended use, such as website authentication.

Linting can expose the use of weak or obsolete cryptographic algorithms and other known insecure practices, improving overall security. Linting improves interoperability and helps CAs reduce the risk of non-compliance with industry standards (e.g., CA/Browser Forum TLS Baseline Requirements). Non-compliance can result in certificates being "mis-issued". Detecting these issues before a certificate is in use by a site operator reduces the negative impact associated with having to correct a mis-issued certificate.

There are numerous open-source linting projects in existence (e.g., certlint, pkilint, x509lint, and zlint), in addition to numerous custom linting projects maintained by members of the Web PKI ecosystem. “Meta” linters, like pkimetal, combine multiple linting tools into a single solution, offering simplicity and significant performance improvements to implementers compared to implementing multiple standalone linting solutions.

Last spring, the Chrome Root Program led ecosystem-wide experiments, emphasizing the need for linting adoption due to the discovery of widespread certificate mis-issuance. We later participated in drafting CA/Browser Forum Ballot SC-075 to require adoption of certificate linting. The ballot received unanimous support from organizations who participated in voting. Beginning March 15, 2025, CAs issuing publicly-trusted certificates must now rely on linting as part of their certificate issuance process.

What’s next?

We recently landed an updated version of the Chrome Root Program Policy that further aligns with the goals outlined in “Moving Forward, Together.” The Chrome Root Program remains committed to proactive advancement of the Web PKI. This commitment was recently realized in practice through our proposal to sunset demonstrated weak domain control validation methods permitted by the CA/Browser Forum TLS Baseline Requirements. The weak validation methods in question are now prohibited beginning July 15, 2025.

It’s essential we all work together to continually improve the Web PKI, and reduce the opportunities for risk and abuse before measurable harm can be realized. We continue to value collaboration with web security professionals and the members of the CA/Browser Forum to realize a safer Internet. Looking forward, we’re excited to explore a reimagined Web PKI and Chrome Root Program with even stronger security assurances for the web as we navigate the transition to post-quantum cryptography. We’ll have more to say about quantum-resistant PKI later this year.

Posted by Christiaan Brand, Group Product Manager

We’re excited to announce that starting today, Titan Security Keys are available for purchase in more than 10 new countries:

• Ireland

• Portugal

• The Netherlands

• Denmark

• Norway

• Sweden

• Finland

• Australia

• New Zealand

• Singapore

• Puerto Rico

This expansion means Titan Security Keys are now available in 22 markets, including previously announced countries like Austria, Belgium, Canada, France, Germany, Italy, Japan, Spain, Switzerland, the UK, and the US.

What is a Titan Security Key?

A Titan Security Key is a small, physical device that you can use to verify your identity when you sign in to your Google Account. It’s like a second password that’s much harder for cybercriminals to steal.

Titan Security Keys allow you to store your passkeys on a strong, purpose-built device that can help protect you against phishing and other online attacks. They’re easy to use and work with a wide range of devices and services as they’re compatible with the FIDO2 standard.

How do I use a Titan Security Key?

To use a Titan Security Key, you simply plug it into your computer’s USB port or tap it to your device using NFC. When you’re asked to verify your identity, you’ll just need to tap the button on the key.

Where can I buy a Titan Security Key?

You can buy Titan Security Keys on the Google Store.

We’re committed to making our products available to as many people as possible and we hope this expansion will help more people stay safe online.