How to secure your mobile application from the design stage

Secure your mobile application by design drastically reduces the risks of data leaks, exploitation of vulnerabilities and subsequent remediation costs by integrating technical and organizational controls throughout the lifecycle.

Security by design: integrating security from the architecture

The choice of an architectural model significantly influences the ability to secure a mobile application. From the needs analysis stage, it is important to identify sensitive data flows, trusted zones, and execution perimeters.

A fictitious company, “NovaPay,” illustrates this common thread: startup fintech created to manage mobile payments, NovaPay has decided to apply the principle of security by design in order to reduce exposure from the first version of its application.

Fundamentals and Threat Modeling

Threat modeling is an essential step in prioritizing measures. It allows you to create attack scenarios and define appropriate controls.

Concrete examples:

• Identify sensitive data (card numbers, identifiers) and classify them by criticality.
• Determine vulnerable areas (local storage, backend API, third-party libraries).
• Map possible attack paths (network interception, device compromise).

This approach helps anticipate attacks and allocate resources to corriger the most critical vulnerabilities.

Secure Architecture: Recommended Patterns

Several architectural patterns improve resilience:

• Backend-for-frontend (BFF) : centralizes business logic and limits the surface area exposed to mobile clients.
• Microservices with secure gateways : insertion of proxies and API gateways to filter and authenticate requests.
• Zero trust : assigns no implicit trust to network components, requiring continuous validations.

NovaPay has adopted a BFF to isolate mobile devices from the critical backend, thus limiting the impact of a client-side compromise.

Summary table of architectural controls

Control	Goal	Element implemented
Segmentation	Limit the spread of attacks	Microservices + private network
Strong authentication	Prevent unauthorized access	MFA, signed tokens
Encryption	Protect data at rest and in transit	TLS 1.3, AES-256 encryption

To apply these principles, it is recommended to rely on robust tools and frameworks. Actors such as Synopsis and Checkmarx offer useful automated code analyses of the design.

Useful links to learn more about secure architecture:

• Technical Fundamentals of Mobile Development
• The fundamentals of cybersecurity
• Pentest and intrusion testing

Insight: A security-first architecture reduces the attack surface and facilitates long-term control maintenance.

Secure Development Practices for Mobile Applications

Secure development practices involve integrating technical and process controls directly into the software development lifecycle (SDLC). They transform development into a proactive rather than a reactive discipline.

Input validation, error handling and dependencies

Input validation must be systematic, both client-side and server-side. Data sanitization prevents common vulnerabilities like SQL injections or XSS adapted to mobile webviews.

• Use proven libraries for validation and sanitization.
• Never expose technical error messages to the client; log details server-side.
• Scan dependencies and avoid outdated or vulnerable versions.

Tools : Synopsis, Checkmarx and SCA/Astro scanners can automate the detection of vulnerable components.

Access control and privilege management

The principle of least privilege must apply at all levels: users, APIs, and internal services. Roles must be clearly defined and reviewed regularly.

• Implement RBAC/ABAC for authentication.
• Check the use of sensitive permissions on the device (location, contacts).
• Automate permission audits to detect abuses.

Example: NovaPay has introduced automated audits that send weekly reports on roles and permissions to prevent the accumulation of unnecessary rights.

Continuous security testing and CI/CD integration

The idea is to integrate security checks into the CI/CD pipeline: SAST/DAST analyses, SCA scans, security unit tests and gates refusing non-compliant builds.

• Configure pipelines to launch SAST/DAST on every PR.
• Block mergers if critical vulnerabilities are detected.
• Perform periodic penetration tests to validate real-life scenarios.

Integration: companies like Capgemini and Sogeti offer security integration and audit services to support these practices.

The video content illustrates practical cases of correction of a data leak related to poor input validation.

Secure Development Checklist

1. Sanitization of incoming data
2. Zero logging of secrets and sensitive data
3. Using secure and versioned APIs
4. Regular code reviews with automated tools
5. Keeping dependencies up to date

Insight: Integrating security into the development pipeline significantly reduces remediation costs and increases user confidence.

Data management and encryption: stored and in transit

Data protection is the central pillar of user trust. It involves encrypting data at rest and in transit, and optimizing key management to prevent compromise.

Encryption and key management

Modern algorithms (TLS 1.3 for transit, AES-GCM for storage) should be implemented according to current recommendations. Key management is as critical as encryption itself.

• Use HSM modules or cloud KMS services to store keys.
• Implement regular key rotation and revocation procedures.
• Avoid including cleartext keys in configurations or code.

NovaPay outsourced key management to a KMS service, reducing the exposure area in the event of a leak on the developer side.

Secure local storage

Local storage on mobile (SharedPreferences, keychain, etc.) should be considered insecure by default. The use of secure boxes or application-layer encryption is required.

• Never store passwords in plain text.
• Use device hardware encryption when available.
• Implement data cleanup after inactivity or uninstallation.

Conformity and protection of personal data

The conformity at RGPD imposes user rights (access, deletion, porability). The application must be designed to facilitate these requests.

• Provide export tools and deletion of user data.
• Document data usage in a clear privacy policy.
• Maintain a register of processing and subcontractors.

Additional resources: Impact of cybersecurity certifications and secure archiving solutions.

Area	Risk	Recommended action
User data	Exfiltration	AES-256 + KMS encryption
API Communication	Interception	TLS 1.3 strict, pinning opportunnel
Logs	PII Leak	Masking, limited retention

Insight: A well-thought-out encryption strategy and rigorous key management protect data even in the event of partial compromise.

Testing, auditing and security ecosystem: tools and processes

The robustness of a mobile application depends on the quality of the tests and audits carried out. This is an ecosystem combining automated tools, manual audits, and bug bounty programs.

Market tools and integration

Several players offer solutions adapted to the needs of teams: SAST/DAST, SCA, mobile pentesting and reverse engineering.

• Synopsis and Checkmarx : SAST analyses and code security.
• Pradeo : specialized solutions in mobile security and protection against malicious applications.
• YesWeHack : bug bounty platform for outsourcing vulnerability research.
• Quarkslab and ITrust : expertise in reverse engineering and audits on demand.
• Orange Cyberdefense and Stormshield : managed security offerings and network solutions.

The joint use of these tools makes it possible to cover all vectors: code, dependencies, configuration and runtime completion.

Manual testing and mobile pentesting

A mobile pentest includes static analysis, dynamic analysis, and stress testing (fuzzing, API manipulation). Engagements must be precise and replicate real-world attack scenarios.

• Prepare a test plan describing the portée and the assets.
• Include testing on different OS and device versions.
• Corrigger and retest: mandatory remediation loop.

Setting up a bug bounty via YesWeHack can extend visibility into vulnerabilities after deployment.

Security Process and Governance

Security is also an organizational discipline: rights management, developer training and implementation of SOPs for incident response.

• Define a security owner for each product.
• Implement an incident response plan and regular exercises.
• Former teams in secure coding and maintaining dependencies.

Integrators like Capgemini and Sogeti can help structure these processes at the enterprise level.

The video illustrates a complete mobile pentest campaign, from scoped recon to the final report.

Insight: Combining automation and manual audits creates a pragmatic and scalable security blanket.

Governance, Conformity and Secure Deployment

The deployment and operations phase requires strict governance. Security policies, regulatory compliance, and maintenance play a major role in product sustainability.

Governance and rights management

Establishing governance involves defining clear roles, rights review processes and periodic checks.

• Schedule quarterly reviews of privileged accounts.
• Automate the removal of lors accesses for departures or changes of position.
• Document responsibilities (SLA, RACI) for incidents.

Practical tip: Integrating automatic revocation via the central directory (LDAP/SCIM) reduces the risk of dormant access.

Conformité, GDPR and regulatory audits

Conformity must be considered by design: consent policies, limited retention and export/erasure capabilities.

• Include access logs to honor GDPR requests.
• Evaluate subcontractors and sign compliant DPAs.
• Prepare Data Protection Impact Reports (DPIAs) if necessary.

Resources : Impact of cybersecurity certifications and the opportunites professions.

Deployment and post-deployment monitoring

Security doesn't stop at store. Continuous monitoring, timely updates, and incident management are essential.

• Set up alerts on abnormal completions (exfiltration, latencies).
• Prepare for fast updates and a secure distribution process via stores.
• Maintain a tamper-proof build and signature chain.

Example: NovaPay has implemented a canary deployment process to quickly detect security regressions without impacting all users.

Insight: Governance and operational oversight ensure that design actions remain effective throughout the lifecycle.

Why is securing your mobile application important?

Securing your mobile app protects user data and reduces financial and reputational risks. A vulnerable app can lead to personal information leaks, account hijacking, and regulatory sanctions; preventive measures limit these impacts.

How to secure your mobile application during design?

To secure your mobile application during design, apply security by design and perform threat modeling. This involves mapping data flows, defining access controls, and choosing resilient architectural patterns.

What tools should you use to secure your mobile application?

To secure your mobile application, combine SAST, DAST, and SCA with manual audits. Solutions like Synopsys, Checkmarx, and Pradeo appor provide appropriate technical coverage.

What are the benefits of securing your mobile app from the start?

Securing your mobile app from the start reduces maintenance costs and improves user confidence. Post-deployment adjustments are often more expensive and time-consuming to implement.

Is securing your mobile app suitable for an m-commerce application?

Yes, securing your mobile application is imperative for a m-commerce application to protect financial transactions and data. Measures such as encryption, forte authentication, and fraud monitoring are necessary.

How to use encryption to secure your mobile application?

To secure your mobile application, use TLS 1.3 for transit and AES-GCM for storage, managing keys via a KMS. Key rotation and protection are essential to maintain confidentiality.

Why do tests and audits help secure your mobile application?

Testing and auditing helps uncover vulnerabilities before they are exploited and improve security posture. They include SAST, DAST, pentests, and bug bounty programs.

How to manage dependencies to secure your mobile application?

To secure your mobile application, regularly scan dependencies with SCA tools and update vulnerable libraries. Avoiding unmaintained packages reduces the risk of introducing vulnerabilities.

Does securing your mobile app require GDPR compliance?

Securing your mobile app means complying with the GDPR if it processes personal data of European users. You must provide access and erasure rights and document processing.

Which providers can help secure your mobile application?

To secure your mobile application, providers like Capgemini, Sogeti, Orange Cyberdefense, and Quarkslab offer audit, integration, and incident response services. They provide complementary expertise.

How to ororganize governance to secure your mobile application?

To secure your mobile application, establish clear roles, rights reviews, and incident processes. Governance ensures the sustainability of measures and the traceability of actions.

What are the benefits for the company if it secures your mobile application?

Securing your mobile application strengthens customer trust, reduces incident costs, and improves regulatory compliance. It can also provide a competitive advantage and limit penalties.