OnSecurity
2 known investors
Find your way into OnSecurity
Each arrow is one introduction. Sign up to fill in the first one.
Ask Chris McIntosh to introduce you to Adam Luxford
You →Chris · together at UK Ministry of Defence →Adam
Ask Jamie Chen to introduce you to Duncan Butchart
You →Jamie · together at Cybergrx →Duncan
Sign up to find every way you can get introduced to OnSecurity
- Your email: who you already know at OnSecurity, and who your contacts know
- 2nd- and 3rd-degree connections: people you know who worked, studied or invested with the OnSecurity team
- Your LinkedIn: the connections who can make the intro for you
We rank every route by how warm it is, so you raise on warm intros instead of cold emails.
OnSecurity provides AI red teaming and penetration testing services to identify vulnerabilities in large language models and AI-powered applications. The company combines manual expert testing with automation to uncover prompt injection attacks, data leaks, API weaknesses, and unsafe model behaviors in AI systems.
Founders & leadership



Investors · 2
Companies House · registry record
View on Companies House ↗- Registered name
- ONSECURITY LLP
- Company number
- OC394445
- Status
- Dissolved
- Company type
- Limited liability partnership
- Incorporated
- 24 Jul 2014
- Dissolved
- 1 Jul 2025
- Registered office
- 1 Victoria Street, Bristol, BS1 6AA
- Accounts
- last made up to 30 Sept 2023
- Confirmation statement
- last made up to 22 Jul 2024
Current officers
- David Robert Hewson — llp designated member, appointed 24 Jul 2014
- Adam Luxford — llp designated member, appointed 24 Jul 2014
- Thomas Alexander Lindley — llp member, appointed 28 Apr 2016
- Conor O'Neill — llp member, appointed 28 Apr 2016
Source: Companies House public register · retrieved 6 Sept 2026. Contains public sector information licensed under the Open Government Licence v3.0.
In the news
Frequently asked questions
- What does OnSecurity do?
- OnSecurity provides AI red teaming and penetration testing services to identify vulnerabilities in large language models and AI-powered applications. The company combines manual expert testing with automation to uncover prompt injection attacks, data leaks, API weaknesses, and unsafe model behaviors in AI systems.
- Who founded OnSecurity?
- OnSecurity was founded by Conor O'Neill.
- Who are OnSecurity's investors?
- OnSecurity's investors include Gresham House Ventures, Osney Capital.



