Two veterans of Israel's Unit 8200 built the most comprehensive GenAI security platform in 18 months — and sold it to SentinelOne for $250 million before turning two.
www.prompt.security ↗Prompt Security is an Israeli-American cybersecurity company founded in August 2023 by Itamar Golan (CEO) and Lior Drihem (CTO), both graduates of the IDF's elite Unit 8200 intelligence corps and alumni of Check Point and Orca Security. The company's enterprise platform secures every AI touchpoint in an organization: browser extensions that monitor employee use of ChatGPT, Claude, and Gemini; code assistant security for GitHub Copilot and Cursor; MCP server governance; and vulnerability assessment for internally built AI applications. With the average enterprise running over 60 AI tools — most unapproved by IT — Prompt addresses a sprawling and rapidly expanding attack surface.
SentinelOne announced a definitive agreement to acquire Prompt Security on August 5, 2025, for approximately $250 million in cash and stock. The deal closed on September 5, 2025, representing a roughly 10x return on Prompt's total $23 million in venture funding (a $5M seed in January 2024, followed by an $18M Series A led by Jump Capital in November 2024, with participation from Hetz Ventures, Ridge Ventures, Okta, and F5). As of early 2026, Prompt Security is operating as an independent platform under SentinelOne, with ARR growing over 100% quarter-over-quarter — the fastest-growing product in SentinelOne's portfolio.
Prompt's platform architecture spans the entire AI interaction chain: it deploys as a browser extension, inline proxy, API gateway integration, and SDK for homegrown applications. The system analyzes every prompt and response in real time to detect sensitive data exposure, block prompt injection and jailbreak attempts, enforce data anonymization, and provide policy-based controls per user and department. Critically, Golan was a core member of the OWASP Top 10 for LLM Applications project, giving Prompt Security deep credibility in defining the threat taxonomy it then commercialized.
Prompt Security is the clearest proof point that AI security is a standalone, venture-scale category — not a feature for existing security vendors to bolt on. Founded in 2023, acquired for $250 million in 2025, and growing ARR at triple-digit rates post-acquisition: this trajectory is exceptional even by cybersecurity M&A standards. For CISOs, Prompt's integration into SentinelOne's Singularity platform means AI security enforcement is now available through an existing enterprise security relationship. For investors, it validates that the window to build category-defining AI security companies is narrowing rapidly as the major platforms absorb the best startups.
Within SentinelOne's ecosystem, Prompt Security occupies the AI security layer that no other component of the Singularity platform previously addressed — making it immediately additive rather than duplicative. Its key competitors are CrowdStrike Falcon AIDR (built on the Pangea acquisition) and Check Point's Lakera integration. Prompt's edge is product depth and velocity: it covers the full spectrum from shadow AI governance to homegrown app security to agentic AI monitoring, and moves at startup speed within a large platform. The risk is whether SentinelOne's go-to-market motion can sustain the product's standalone momentum, or whether it becomes absorbed and deprioritized in a broader platform narrative.
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