HiddenLayer vs Prompt Security

HiddenLayer is an Austin, Texas-based AI security company founded in March 2022 by experienced cybersecurity and machine learning professionals. The company provides a comprehensive AI Security Platform covering AI Discovery (automated inventory), AI Supply Chain Security (model scanning for embedded threats), AI Attack Simulation (red teaming), and AI Runtime Security (guardrails and active threat response). The platform is designed to be non-invasive — protecting models without requiring access to raw training data — and integrates with CI/CD, MLOps, data pipelines, and SIEM/SOAR tools. HiddenLayer is recognized by Gartner as a Cool Vendor for AI Application Security. The company raised $50M in Series A in September 2023, the largest Series A for an AI-focused cybersecurity company at that time, led by M12 (Microsoft's Venture Fund) and Moore Strategic Ventures. Customers include enterprises in financial services, US federal government, and technology. Named endorsers include the CISO of the NFL and the former CISO of AIG.

Prompt Security is a Tel Aviv-based AI security company founded in August 2023 by Itamar Golan (CEO) and Lior Drihem (CTO), both alumni of Israel's elite Unit 8200 with prior experience at Check Point and Orca Security. The company provides an enterprise platform for securing all generative AI interactions — covering employee AI tool usage (shadow AI discovery, data protection), homegrown AI applications (prompt injection defense, output filtering), AI code assistants, and agentic AI security including MCP gateway protection. Prompt Security is a core contributor to the OWASP Top 10 for LLM Applications. The company raised $23M prior to its acquisition by SentinelOne, which was completed on September 5, 2025. Prompt Security continues to operate as a standalone platform and product brand within SentinelOne's Singularity platform. CRN named it a 2025 Stellar Startup in Security.