Best Security Audit Companies
Overview
Forward Email has been actively evaluating cybersecurity research companies to conduct comprehensive audits of our open-source codebase on GitHub and server infrastructure. After extensive research and evaluation over the past few years, we have identified several exceptional security audit firms that consistently demonstrate high-quality work, technical expertise, and alignment with our privacy-focused values.
This document represents our findings and recommendations for organizations seeking professional security audit services. The companies listed here have all shown exceptional capabilities in penetration testing, code review, infrastructure assessment, and security research.
Our Evaluation Process
Our evaluation process focused on several key factors that are critical for organizations requiring thorough security assessments. We examined each company's track record, technical expertise, transparency in reporting, and commitment to open-source principles. The companies featured in this guide have all demonstrated consistent excellence during our multi-year evaluation period.
It is important to note that the companies listed below are not ranked in any particular order. Each organization brings unique strengths and specializations to the cybersecurity field, and the best choice depends on specific project requirements, budget considerations, and organizational needs.
Recommended Security Audit Companies
Cure53
Location: Berlin, Germany Website: https://cure53.de/ Specialization: "Fine penetration tests for fine websites"
Cure53 is a German cybersecurity firm renowned for their meticulous approach to web application security testing and penetration testing. Based in Berlin, they have established themselves as leaders in the field through their comprehensive testing methodologies and detailed reporting practices.
The company has built an impressive portfolio of security assessments for high-profile clients and open-source projects. Their work demonstrates a deep understanding of modern web technologies, cryptographic implementations, and infrastructure security. Cure53's reports are particularly notable for their technical depth and actionable recommendations.
Notable Publications and Reports:
- Mullvad Servers Security Assessment 2024 - Comprehensive infrastructure security evaluation
- Mullvad Apps/API Security Assessment 2020 - Application and API security analysis
- Mullvad Servers Security Assessment 2021 - Follow-up infrastructure assessment
Radically Open Security
Location: Amsterdam, The Netherlands Website: https://www.radicallyopensecurity.com/ Specialization: "Non-Profit Computer Security Consultancy"
Radically Open Security (ROS) operates as a unique non-profit computer security consultancy that aligns perfectly with open-source principles and transparency values. Based in Amsterdam, ROS has pioneered an innovative approach to security consulting by making their methodologies and findings publicly available whenever possible.
Their non-profit model allows them to focus purely on security outcomes rather than profit maximization, which often results in more thorough assessments and genuine recommendations. ROS has particular expertise in privacy-focused technologies, VPN services, and applications that handle sensitive user data.
Notable Publications and Reports:
- Droid2Tracking Security Assessment - Mobile tracking analysis
- Tauri Programme Security Assessment 2022 - Cross-platform application framework evaluation
- Mullvad VPN Security Assessment 2022 - VPN service security analysis
Assured AB
Location: Gothenburg, Sweden Website: https://www.assured.se/ Specialization: "Experts in technical cybersecurity"
Assured AB is a Swedish cybersecurity consultancy that has established itself as a leader in technical cybersecurity assessments. Based in Gothenburg, they bring deep technical expertise to complex security challenges, particularly in areas involving email infrastructure, DNS security, and API assessments.
The company's approach emphasizes thorough technical analysis combined with practical, implementable recommendations. Their reports demonstrate exceptional attention to detail and a comprehensive understanding of modern security threats and mitigation strategies.
Notable Publications and Reports:
- Mullvad Email Servers Security Audit 2024 - Email infrastructure security assessment
- Mullvad API Security Audit 2022 - API security evaluation
- Mullvad DNS Server Security Audit 2022 - DNS infrastructure assessment
Trail of Bits
Location: New York, New York, United States Website: https://www.trailofbits.com/ Specialization: "We don't just fix bugs, we fix software."
Trail of Bits is a prominent American cybersecurity firm that has earned recognition for their innovative approach to software security. Based in New York, they have developed cutting-edge tools and methodologies that have advanced the entire cybersecurity field. Their motto, "We don't just fix bugs, we fix software," reflects their commitment to addressing systemic security issues rather than just surface-level vulnerabilities.
The company has particular expertise in blockchain security, cryptographic implementations, and complex software systems. Trail of Bits is also known for their contributions to open-source security tools and their thought leadership in emerging security domains.
Notable Publications and Reports:
- Homebrew Security Review 2023 - Package manager security assessment
- Hey Security Review - Email service security evaluation
- cURL Security Review 2022 - Network library security analysis
Company Comparison
| Company | Location | Focus Area | Notable Strengths | Public Reports |
|---|---|---|---|---|
| Cure53 | Berlin, Germany | Web Application Security | Detailed penetration testing, comprehensive reporting | 3+ Mullvad assessments |
| Radically Open Security | Amsterdam, Netherlands | Privacy & Open Source | Non-profit model, transparency, VPN expertise | Public methodology sharing |
| Assured AB | Gothenburg, Sweden | Technical Infrastructure | Email/DNS security, API assessments | Specialized server audits |
| Trail of Bits | New York, USA | Software Security | Blockchain, cryptography, security tooling | Open-source contributions |
Selection Criteria
When evaluating these security audit companies, we considered several critical factors that organizations should assess when selecting a security partner:
Technical Expertise: All recommended companies demonstrate deep technical knowledge across multiple domains including web application security, infrastructure assessment, cryptographic implementations, and emerging technologies.
Transparency and Reporting: Each firm provides comprehensive, actionable reports that clearly communicate findings, risk assessments, and remediation strategies. Many also contribute to the broader security community through public research and open-source tools.
Track Record: The companies listed have established proven track records with high-profile clients and complex security challenges. Their public reports demonstrate consistent quality and thoroughness.
Alignment with Values: For organizations prioritizing privacy, open-source principles, and transparency, these companies have shown commitment to these values through their work and business practices.
Continuous Improvement: All recommended firms stay current with evolving threat landscapes and emerging technologies, ensuring their assessments remain relevant and comprehensive.
The security audit landscape continues to evolve, and we recommend organizations conduct their own evaluation based on specific needs, budget constraints, and project requirements. However, any of these companies would provide exceptional security assessment services for organizations serious about protecting their infrastructure and user data.