Prompt Security is an AI security platform that protects organizations against prompt injection, data leakage, and shadow AI across both employee GenAI usage and homegrown LLM applications.
Co-founded in August 2023 by Itamar Golan and Lior Drihem in Tel Aviv, Israel, Prompt Security grew rapidly to become a prominent GenAI security platform.
The company was named a 2025 SINET16 Innovator for its AI security capabilities.
In August 2025, SentinelOne signed a definitive agreement to acquire Prompt Security for undisclosed consideration, integrating the platform into SentinelOne’s Singularity cybersecurity suite to address GenAI and agentic AI security at the endpoint and runtime level.
What is Prompt Security?
Prompt Security takes a full-stack approach to GenAI security. Its value, as I read it, is covering employee GenAI usage and homegrown LLM applications in one policy layer.
The platform inspects all interactions with GenAI tools in real time. For employee-facing AI usage, a browser extension monitors prompts, file uploads, and responses across 250+ AI models.
For homegrown applications, an API integration screens inputs and outputs for injection attempts, data exfiltration, and policy violations. Detection runs with sub-200ms latency, and the system can block, redact, or alert depending on the configured policy.
| Capability | Details |
|---|---|
| Prompt Injection Protection | AI-powered engine detects and blocks adversarial prompt injection attempts in real time across homegrown LLM applications. Covers direct injection, indirect injection, jailbreaks, and system prompt extraction with sub-200ms response times. |
| Shadow AI Discovery | Detects all employee usage of GenAI tools — including unapproved services — via browser extension and network monitoring. Provides real-time visibility into which AI tools are being used and what data is being shared. |
| Data Leakage Prevention | Uses semantic analysis and contextual filters to detect and redact PII, PHI, financial data, and proprietary information before it reaches external GenAI tools or leaves homegrown applications. Supports custom data classification policies. |
Key Features
| Feature | Details |
|---|---|
| Prompt Injection Detection | Direct, indirect, jailbreak, system prompt extraction |
| Response Latency | Sub-200ms for real-time detection |
| Model Support | 250+ AI models via unified interface |
| Shadow AI Detection | Browser extension + network-level visibility |
| Data Protection | PII, PHI, financial data detection and redaction |
| Deployment Options | SaaS, on-premises, browser extension (Chrome) |
| Red Teaming | Built-in testing with custom LLMs |
| Content Filtering | Customizable policies with role-based controls |
| Compliance | Encryption at rest and in transit, customizable retention policies |
| Integration | Browsers, desktop apps, APIs |
Browser extension
The Prompt Security browser extension is the primary tool for monitoring employee GenAI usage. It deploys in minutes via Intune or similar MDM solutions and works by dynamically detecting GenAI interactions through DOM analysis and user action tracking — typing, pasting, clicking, and file uploads.
Organizations can start in monitor-only mode to gain visibility into GenAI usage patterns before enforcing policies. Once policies are active, the extension can block risky prompts, redact sensitive data in real time, or alert administrators based on configurable rules.
Data leakage prevention
The platform uses semantic analysis rather than simple pattern matching to identify sensitive information.
It detects PII, PHI, financial data, source code, and proprietary information contextually, accounting for how data appears within natural language prompts.
When sensitive data is detected, the system can redact it automatically, block the interaction, or send an alert to the platform admin with full logging.
Red team testing
Prompt Security includes built-in red teaming capabilities that test your LLM applications against known attack patterns. The platform generates adversarial prompts using custom LLMs to probe for vulnerabilities including injection, data extraction, and policy bypasses.
SentinelOne acquired Prompt Security in August 2025 for undisclosed consideration. The acquisition integrates Prompt Security’s GenAI protection into SentinelOne’s Singularity platform, adding AI-native security capabilities across endpoints, browsers, and runtime environments.
Prompt Security continues to operate as part of SentinelOne’s AI security strategy.
Getting Started
- Choose your deployment — Prompt Security is available as SaaS, on-premises, or via browser extension. Employee monitoring starts with the Chrome extension; application protection uses the API integration.
- Deploy the browser extension — Push the Chrome extension via Intune or MDM to monitor employee GenAI usage. Start in monitor-only mode to map shadow AI usage across the organization.
- Configure data protection policies — Define which data types to detect (PII, PHI, source code, financial), set redaction or blocking rules, and assign role-based access controls for teams and individual users.
- Integrate with homegrown apps — Add the Prompt Security API to your LLM-powered applications to screen inputs and outputs for prompt injection, data leakage, and content policy violations.
- Monitor and enforce — Use the dashboard to review GenAI usage analytics, shadow AI reports, and security incidents. Tune policies and move from monitoring to active enforcement as confidence grows.
When to use Prompt Security
Prompt Security fits organizations that need to secure GenAI usage on two fronts: controlling how employees interact with third-party AI tools, and protecting homegrown LLM applications from adversarial attacks.
The browser extension approach gives security teams visibility into shadow AI without requiring network-level inspection, and the sub-200ms detection latency keeps the user experience intact.
The platform is especially relevant for regulated industries — healthcare, financial services, government — where data leakage to AI tools is a compliance risk and where prompt injection in production applications could expose sensitive information.
For a broader overview of AI security risks, see the AI security guide . For API-focused runtime protection with lower latency, consider Lakera Guard .
For open-source input/output guardrails, see LLM Guard or NeMo Guardrails . For AI red teaming specifically, look at Garak or Mindgard .
Prompt Security alternatives
The closest direct alternative is Lakera — also acquired in 2025 (Check Point), with a sub-50ms API-first runtime guardrail that fits teams who prioritize latency on the homegrown-app side over browser-based shadow AI discovery. WitnessAI competes on the enterprise gateway pattern with intent-based behavioral controls and single-tenant data sovereignty.
Noma Security covers a broader AI security posture surface — agent inventory, MCP security, and runtime defense — for organizations that need governance scope beyond GenAI usage. CalypsoAI is a peer enterprise platform with strong public-sector traction.
For open-source teams, LLM Guard provides input and output scanners as a self-hosted Python library, and NeMo Guardrails supports programmable safety policies. The AI security tools hub maps the full set.