---
title: "Locke vs VPN and Zero Trust Network Access"
description: "VPN and ZTNA control which AI services employees can reach. They don't control what data goes into prompts on those services. Why both layers are needed."
url: "https://sonomos.ai/compare/sonomos-vs-vpn-zero-trust/"
source: "https://sonomos.ai/compare/sonomos-vs-vpn-zero-trust/"
---

# Locke vs VPN and Zero Trust Network Access

VPN and Zero Trust Network Access (ZTNA) secure the transport layer and enforce who can connect to what. A ZTNA policy can stop an employee from reaching an unapproved AI provider. It can't stop them from typing an SSN into an approved one.

## When VPN and Zero Trust Network Access fits

- You need to control which AI services employees can access at the network level, blocking unsanctioned providers entirely.
- Your security architecture requires all traffic to route through a corporate egress point for visibility and logging.
- You need to enforce identity and device posture requirements before any AI service can be reached.

## When Locke fits

- You have already decided which AI tools are approved and want to control what data goes into prompts on those tools.
- You want to govern what sensitive content reaches approved tools, not block them.
- You need on-device control that operates at the content level, not the connection level.

## Side-by-side

| Dimension | Locke | VPN and Zero Trust |
| --- | --- | --- |
| What it controls | What specific data fields appear in prompts (field-level content control). | Which services can be reached (connection-level access control). |
| Where it operates | At the device, inside the browser, at the moment of prompt composition. | At the network layer, between the device and the destination. |
| Can it prevent PHI from reaching an approved AI tool? | Yes. Masks or removes sensitive data before submission. | No. Only controls whether the connection is allowed, not the content. |
| Covers unsanctioned browser-based AI tools | Yes. Same controls on any AI chat interface regardless of policy status. | Can block access entirely; cannot inspect the content of allowed tools. |
| Best for | Controlling what sensitive data reaches approved AI services. | Controlling which AI services employees can access at all. |

## Bottom line

VPN and Zero Trust control access to AI services. Locke controls the content that reaches them. Most organisations serious about AI risk end up wanting both: ZTNA to approve the tools, and Locke so even approved tools never see the most sensitive fields.

[Download Locke](https://sonomos.ai/downloads/)[See the Locke demo](https://sonomos.ai/locke/#demo)[See pricing](https://sonomos.ai/pricing/)[Talk to the team](https://sonomos.ai/contact/)

## Related comparisons

- [Locke vs Cloud-Based Data Loss Prevention](https://sonomos.ai/compare/sonomos-vs-cloud-dlp/)
- [Locke vs Enterprise Privacy Platforms](https://sonomos.ai/compare/sonomos-vs-enterprise-privacy/)
- [Locke vs AI API Gateways and Proxies](https://sonomos.ai/compare/sonomos-vs-ai-gateway/)

[View all comparisons](https://sonomos.ai/compare/)

## Further reading

- [The Best AI Privacy Tools for ChatGPT, Claude, and Gemini (2026)](https://sonomos.ai/blog/best-ai-privacy-tools-chatgpt-claude-gemini-2026/)
- [AI Data Leakage: 7 Ways Sensitive Information Escapes to LLMs (and How to Stop It)](https://sonomos.ai/blog/ai-data-leakage-7-ways-sensitive-info-escapes-to-llms/)
- [What Is PII Redaction? A Plain-English Guide for AI Users](https://sonomos.ai/blog/what-is-pii-redaction-ai/)