Harmonic Security Raises $50 Million for Workforce AI Protection

Founded in 2023 by Alastair Paterson (CEO) and Bryan Woolgar-O’Neil (CTO), who previously founded Digital Shadows—which was later acquired by ReliaQuest—Harmonic built an innovative platform designed specifically to secure artificial intelligence tools for corporate employees. As organizations across the globe grapple with the rapid adoption of generative AI, large language models, and automated workplace workflows, securing these deployments has become a paramount concern for chief information security officers and corporate boards alike.

The newly announced Series B funding round was led by Crosspoint Capital Partners, a prominent investment firm specializing in cybersecurity and infrastructure software, with additional participation and strong ongoing support from the company’s existing investors. This fresh injection of capital will be strategically utilized by Harmonic Security to significantly expand its engineering and go-to-market teams across both the United States and the United Kingdom, scaling operations to meet accelerating enterprise demand.

The rapid rise of Harmonic Security reflects a broader, fundamental shift in how modern enterprises operate. Employees everywhere are rapidly integrating artificial intelligence into their daily routines, utilizing everything from browser-based chat assistants and standalone desktop AI tools to complex, autonomous agentic workflows. While these technologies offer unprecedented productivity gains and streamline everyday business tasks, they also introduce significant security and compliance vulnerabilities that traditional data loss prevention tools and legacy cybersecurity solutions are simply not equipped to handle.

Harmonic’s comprehensive security solution is engineered to address this exact operational blind spot. The platform covers browser-based AI, desktop AI applications, and agentic workflows, operating continuously to classify every single AI task, identify its specific use case, and provide real-time control over user interactions. By monitoring how employees engage with artificial intelligence across various endpoints and applications, the startup’s expanded coverage effectively exposes a wide array of emerging enterprise risks, including unauthorized personal-account usage, accidental sensitive data exposure, intellectual property leakage, and compliance violations that could otherwise jeopardize an organization’s security posture.

At the technological core of Harmonic’s platform is a specialized approach leveraging custom small language models. Instead of relying solely on broad, generalized security parameters, the startup utilizes these compact language models to read and analyze each individual AI interaction within its proper context. This contextual awareness enables corporate organizations to accurately categorize complex tasks, understand emerging enterprise use cases, and apply precise, real-time security controls without unnecessarily hindering employee productivity or slowing down business innovation.

Furthermore, the same underlying engine powers Harmonic’s Usage Intelligence layer. This distinct feature offers organizations deep, actionable visibility into the specific AI use cases that genuinely create business value and measurably improve employee workflows. In today’s corporate landscape, leadership teams are no longer just looking to block unauthorized technologies; they are actively trying to understand return on investment and identify which tools are driving efficiency.

Alastair Paterson, co-founder and chief executive officer of Harmonic Security, highlighted this dual mandate during the announcement of the company’s latest funding milestone. Reflecting on conversations with corporate leaders, Paterson noted that the pressures facing executive leadership and boardrooms have evolved rapidly over the past few years.

"Every board I talk to is asking two questions: how do we reduce the risk of AI use, and are we getting value? Most vendors struggle to answer the first, yet we address both. From the very start, we doubled down on our custom small language models, which means we can benefit from a unique insight into enterprise AI use," Paterson explained.

The successful completion of this $50 million Series B financing round places Harmonic Security in a strong competitive position within the burgeoning workforce AI security sector. As artificial intelligence continues to transform the modern workplace, startups and established cybersecurity vendors alike are racing to provide robust runtime and operational safeguards. Recent market activity highlights this intense industry focus, with companies like Rein Security raising funding to guard AI agents at runtime, Hadrian securing capital to expand autonomous offensive security platforms, doxx.net securing investments to prevent internet-based AI agent misadventures, and Osavul raising funds to spot hostile intent across cyber and physical domains.

With its total funding now reaching $76 million, Harmonic Security plans to use its strengthened financial backing to further refine its core technology, deepen its market penetration, and help enterprises safely navigate the complex intersection of workplace productivity and artificial intelligence security.