Mobile app security: the essentials every business should insist on

A mobile app carries your brand into your customers' pockets, and often their personal data, payment details and account access too. A single security lapse can cost far more than the app itself, in lost trust as much as in money. The good news is that most problems are prevented by a handful of well-understood practices.

Here is what to expect from any team building an app for you, whether you have a security background or not.

1. Keep secrets off the device

Anything shipped inside an app can be extracted. API keys with broad permissions, database passwords and admin credentials must never be built into the app. Sensitive operations belong on your server, where you control access.

2. Store data on the phone carefully

• Store only what the app genuinely needs on the device.
• Use the platform's secure storage (Keychain on iOS, Keystore on Android) for tokens and sensitive values.
• Don't write personal data to logs, caches or screenshots.

3. Protect data in transit

All traffic should use HTTPS with modern settings. For apps handling payments or sensitive records, certificate pinning makes it much harder for an attacker on the same network to intercept traffic.

4. Get authentication right

• Use short-lived access tokens that refresh automatically, so a stolen token expires quickly.
• Offer biometric login for convenience, backed by proper server-side sessions.
• Support multi-factor authentication for admin accounts and sensitive actions.
• Let users see and end their active sessions.

5. Never trust the app alone

The server must check every request: is this user allowed to see this record, change this order, use this discount? Checks that only happen inside the app can be bypassed. This single principle prevents a large share of real-world breaches.

6. Keep dependencies up to date

Most apps include dozens of third-party libraries. Each one can contain vulnerabilities. Track them, update regularly, and remove what you no longer use. Be particularly careful with analytics and advertising SDKs, which may collect more data than you expect.

7. Ask only for permissions you need

Location, contacts, camera and microphone access should be requested only when a feature needs them, with a clear explanation. App stores increasingly reject apps that over-ask, and users notice.

8. Respect privacy rules

Depending on where your users are, laws such as India's DPDP Act, the EU's GDPR or the UAE's data protection law apply. In practice that means a clear privacy policy, collecting the minimum data, letting users delete their account and data, and filling in the App Store and Google Play privacy declarations accurately.

A pre-launch checklist

1. No secrets in the app bundle
2. Sensitive data in secure storage only
3. HTTPS everywhere, pinning where it matters
4. Server-side permission checks on every endpoint
5. Dependencies reviewed and updated
6. Minimum permissions, each clearly explained
7. Privacy policy, account deletion and store declarations in place
8. An independent security test for apps handling payments or personal data

After launch

Security isn't a one-off task. Plan for regular updates, monitor for unusual activity, and have a simple plan for what to do and who to tell if something goes wrong.

Building an app, or want a second opinion on an existing one? See how we build mobile apps or get in touch.