HiddenLayer vs Protect AI (2026): Which AI Security Platform Is Right for You?

A practical comparison of the two leading platforms for securing AI models and applications — including what Palo Alto Networks' acquisition of Protect AI means for buyers.

Published by Picari | picari.io | May 2026

TL;DR

Both HiddenLayer and Protect AI are strong platforms for securing AI models — but they suit different buyers. HiddenLayer is the better fit for teams that want a focused, independent vendor with flexible deployment (including air-gapped). Protect AI, now part of Palo Alto Networks, offers broader coverage and is the natural choice for organisations already in the Palo Alto ecosystem.

Introduction

AI security is one of the fastest-growing and least-understood categories in cybersecurity. As organisations rush to deploy large language models, ML pipelines, and agentic AI systems, a new class of risk has emerged — and a new class of vendor with it.

Two names consistently come up when security teams start evaluating this space: HiddenLayer and Protect AI. Both were founded in 2022, both have raised significant funding, and both cover the core problem of protecting AI models from supply chain attacks, adversarial inputs, and runtime exploitation.

But there is now a major structural difference between them: Protect AI was acquired by Palo Alto Networks in early 2026, integrating its technology into the Prisma AIRS platform. HiddenLayer remains independent.

This guide breaks down where each platform is strongest, who they are built for, and what the acquisition means if you are evaluating both.

Company Backgrounds

HiddenLayer

HiddenLayer was founded in 2022 and has raised approximately $56 million. The company has remained independent and focused exclusively on AI and ML model security. Its AISec Platform 2.0 — unveiled at RSAC 2025 — covers four pillars: AI discovery, supply chain security, attack simulation, and runtime defence.

HiddenLayer positions itself as a non-invasive, deployment-flexible solution suitable for enterprises with strict data residency or compliance requirements.

Protect AI (now part of Palo Alto Networks)

Protect AI was also founded in 2022 and raised roughly $108 million before its acquisition. The company built a three-product platform — Guardian (pre-deployment scanning), Layer (runtime protection), and Recon (automated red teaming) — alongside a meaningful open-source portfolio including ModelScan, NB Defense, and LLM Guard.

Protect AI also operates huntr.com, the world's largest AI and ML bug bounty platform. In early 2026, the acquisition by Palo Alto Networks was completed, with Protect AI's technology folded into Prisma AIRS.

Deeper Look: Where Each Platform Shines

Pre-Deployment Model Scanning

Both platforms scan AI model files before they enter production — checking for malicious code injections, deserialization exploits (particularly in pickle-based formats), and architectural backdoors. Both support 35+ model formats including PyTorch, TensorFlow, ONNX, Keras, and GGUF.

Protect AI's Guardian has an edge in supply chain coverage: it continuously scans over 1.5 million public models on Hugging Face, meaning known-bad models are flagged before your team even downloads them. It also generates an AI Bill of Materials (AI-BOM), which is increasingly relevant for compliance and governance.

HiddenLayer's ModelScanner is equally capable for internal model scanning and works across all major deployment environments including air-gapped systems — a meaningful differentiator for defence, government, and regulated industries.

Runtime Defence

Runtime protection — detecting and blocking attacks against deployed models — is where HiddenLayer has historically been strongest. Its platform is designed to be non-invasive, sitting alongside production systems without requiring deep integration.

Protect AI's Layer product covers runtime security with 27 pre-built policies backed by 15 security scanners. The breadth is impressive, though smaller security teams may find it requires more configuration than HiddenLayer's approach.

Red Teaming and Attack Simulation

Protect AI's Recon product is a standout here. It runs automated red teaming across six major threat categories and — critically — tests the full AI application stack, not just the underlying model. This means it accounts for RAG pipelines, system prompts, guardrails, and business logic when generating attack scenarios.

HiddenLayer includes attack simulation as part of its AISec Platform 2.0, though it is less differentiated in this area than Recon.

Open Source and Community

Protect AI has built a significant open-source presence: ModelScan, NB Defense, and LLM Guard are widely used tools, and huntr.com is the largest bug bounty platform focused specifically on AI and ML vulnerabilities. This gives security teams a lower-friction way to get started and contributes to Protect AI's broader threat intelligence.

HiddenLayer has no open-source offering. For teams that weight vendor community and ecosystem tools, this is a gap worth noting.

The Palo Alto Networks Acquisition: What It Means for Buyers

The acquisition of Protect AI is the single biggest factor that differentiates these two platforms in 2026. Here is what it means in practice.

Potential advantages:

Organisations already using Palo Alto tools (Prisma Cloud, Cortex, etc.) gain a more integrated AI security posture through Prisma AIRS
Enterprise-grade support, SLAs, and account management come with the Palo Alto relationship
Palo Alto's global threat intelligence feeds can potentially enrich Protect AI's detection capabilities over time

Potential concerns:

Product roadmap decisions will now be driven by Palo Alto's priorities, not Protect AI's original team vision
Pricing and packaging may shift as the product is absorbed into the Palo Alto portfolio
Teams that valued Protect AI's independence and speed of iteration may find the larger company context slows things down
The open-source tools (ModelScan, LLM Guard) remain available, but their long-term direction under Palo Alto ownership is less certain

Key question to ask Palo Alto: Will Protect AI's products continue to be sold and supported independently, or will they be bundled exclusively into Prisma AIRS? The answer should significantly influence your evaluation.

Who Should Choose Which

Choose HiddenLayer if...

You want a pure-play, independent AI security vendor with a single focus
You require flexible deployment: on-premises, air-gapped, or hybrid environments
Your primary concern is adversarial runtime attacks against deployed models
You are in a regulated or sensitive industry (defence, government, healthcare) with strict data residency requirements
You prefer not to be locked into the Palo Alto ecosystem

Choose Protect AI (Palo Alto) if...

You are already a Palo Alto Networks customer and want AI security integrated into your existing stack
You need the broadest possible coverage — supply chain, pre-deployment, runtime, and red teaming — from a single vendor
Your team uses or contributes to open-source AI security tooling and values community-driven threat intelligence
You are building or managing AI applications on Hugging Face and want continuous third-party model scanning
You have the security team bandwidth to configure and manage a broader platform

Verdict

HiddenLayer and Protect AI both address a genuine and growing problem. In a category where most enterprise security tools are retrofitted to handle AI as an afterthought, both platforms were purpose-built for it.

For most enterprise buyers in 2026, the decision comes down to ecosystem fit. If you are a Palo Alto shop, the path of least resistance is Protect AI via Prisma AIRS — you get broad coverage and a familiar commercial relationship. If you want a focused, independent vendor with no vendor lock-in and flexible deployment options, HiddenLayer is the stronger standalone choice.

One thing is clear: the category is no longer optional. As AI becomes central to business operations, securing models and pipelines is as important as securing networks and endpoints.

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HiddenLayer vs Protect AI: Which AI Security Platform Is Right for Your Team?