🔍 Open Source vs Security Through Obscurity

When it comes to protecting your data, two approaches dominate the conversation: open source and security through obscurity.

One makes its code fully available for anyone to inspect.
The other keeps its inner workings hidden, betting that secrecy itself will keep attackers at bay.

So which approach is better? Let’s break it down — with real-world examples from password managers, VPNs, and mobile operating systems.

🛠 What Is Open Source Security?

Open source means the software’s source code is publicly available. Anyone — independent researchers, competing developers, even hackers — can see exactly how it works.

Examples:

• Password Managers: Bitwarden and KeePass are both open source, allowing independent audits and community bug fixes. See our list of best password managers for other options.
• VPNs: Providers like Proton VPN and [Mullvad] publish their app code for verification, similar to some on our best VPNs list.
• Operating Systems: Linux is the gold standard in open source OS security.
• Mobile Apps: Many Android apps are released as open source on platforms like GitHub, making it easier to spot privacy risks.

Pros:

• ✅ Transparency — Flaws can be spotted and fixed faster
• ✅ Community Audits — More eyes = higher chance of catching mistakes
• ✅ Trust Building — Users can verify there are no hidden data collection routines or backdoors
• ✅ Longevity — If the company dies, the code can still be maintained by the community

Cons:

• ⚠️ Exposes Weaknesses — Vulnerabilities are visible to attackers too (but this also applies to defenders)
• ⚠️ Quality Varies — Open code isn’t automatically good code; it still depends on active, skilled maintenance

🕵️‍♂️ What Is Security Through Obscurity?

Security through obscurity means the source code, design, or method is kept secret. The idea: if attackers don’t know how it works, it’s harder to break.

Examples:

• Password Managers: Dashlane and 1Password are closed-source; you have to trust their audits and security claims.
• VPNs: ExpressVPN is closed-source (except for its browser extensions) but relies on independent audits to build trust — see how it compares to no-log VPNs.
• Operating Systems: Apple’s iOS is closed-source — its security relies on internal review and controlled distribution.
• Mobile Apps: Many proprietary Android/iOS apps keep their code hidden, making it impossible for users to verify privacy practices.

Pros:

• ✅ Initial Barrier — Obscurity can slow down opportunistic attacks
• ✅ IP Protection — Keeps proprietary methods away from competitors
• ✅ Controlled Access — Only trusted insiders see the code

Cons:

• ⚠️ False Sense of Security — Attackers can reverse-engineer software or discover vulnerabilities without the source code
• ⚠️ Slower Fixes — Without outside review, flaws can remain hidden for years
• ⚠️ Trust Issues — Users have to take the vendor’s word on security claims

🔄 How They Compare

⚠️ The Real-World Risk of Obscurity

Relying solely on secrecy has burned companies before.
Attackers often reverse-engineer binaries, sniff network traffic, or exploit known patterns in proprietary systems.

For example:

• Closed-source VPN apps have been caught logging user activity despite “no logs” claims — see our article on what are no-log VPNs.
• Some iOS and Android apps request far more permissions than needed — something that’s easier to hide without public code.
• Proprietary password managers have had breaches where the vulnerability could have been caught earlier with more eyes on the code.

Once a flaw is found in closed software, users are dependent on the vendor to fix it — and that can take months or even years.

Open source isn’t perfect either. If a project is abandoned or poorly maintained, vulnerabilities can pile up. The key difference? You can see the state of the project and choose to patch or fork it yourself.

💡 The Best Approach

Security experts agree: obscurity can be part of a defense-in-depth strategy, but it should never be the only line of defense.

The ideal is:

• Open, reviewable code
• Strong encryption
• Regular third-party audits
• Minimal trust placed in any one actor
• Transparent policies on logging, permissions, and data handling

🗣️ Final Word

Whether it’s your password manager, VPN, operating system, or mobile app, transparency builds trust. Obscurity can add friction for attackers, but without independent verification, you’re betting your security on secrecy — and that bet rarely pays off in the long run.

If you can audit it, you can trust it. If you can’t, you have to hope.