How to Secure Your Android and iOS Smartphone and Tablets

Securing your mobile devices requires a multi-layered approach combining built-in security features with smart habits. Essential steps include:

• Enabling biometric authentication (Face ID, fingerprint)
• Activating two-factor authentication (2FA) on all accounts
• Keeping your operating system updated
• Managing app permissions carefully
• Using strong encryption

For example, Android 15’s new Theft Detection Lock automatically locks your screen if someone snatches your device, while iOS offers Stolen Device Protection that requires Face ID for sensitive actions in unfamiliar locations. Additional protections like VPNs for public Wi-Fi, secure cloud backups with encryption, and regular security audits ensure comprehensive device protection against theft, malware, and unauthorized access.

Enable Strong Authentication Methods

Biometric authentication represents your first line of defense. Both Android and iOS devices support fingerprint scanning and facial recognition, which are significantly more secure than PIN codes alone.

Android Setup Instructions:

1. Open Settings
2. Navigate to Security or Security & privacy
3. Select Biometric preferences or Device unlock
4. Choose Fingerprint or Face unlock
5. Follow the on-screen prompts to register your biometric data
6. Create a strong backup PIN (at least 6 digits) when prompted
7. Enable Secure lock screen settings
8. Set Auto-wipe data after failed attempts:
   • Go to Settings > Security > Lock screen preferences
   • Enable Auto-wipe device after 10 failed unlock attempts

iOS Setup Instructions:

1. Open Settings
2. Tap Face ID & Passcode or Touch ID & Passcode
3. Enter your current passcode if prompted
4. Select Set Up Face ID or Add a Fingerprint
5. Follow the on-screen instructions to scan your face or fingerprint
6. Create a strong alphanumeric passcode (recommended over 6-digit numeric)
7. Enable Require Attention for Face ID for added security
8. Enable Erase Data after 10 failed passcode attempts:
   • Scroll down in Face ID & Passcode settings
   • Toggle on Erase Data
   • Confirm your choice when prompted

Important Security Considerations

According to the NSA’s mobile device best practices, a 6-digit PIN is sufficient if your device automatically wipes after 10 failed attempts. The auto-wipe feature provides crucial protection against brute-force attacks by permanently erasing all data after repeated unauthorized access attempts.

Important Note for International Travelers: If you frequently cross international borders, carefully consider whether to enable the auto-wipe feature. Border security personnel in some countries may request device access, and multiple failed unlock attempts by authorities could trigger the auto-wipe function, resulting in permanent data loss. Travelers should:

• Back up your device before international travel
• Consider temporarily disabling auto-wipe when crossing borders
• Use cloud services to store non-sensitive data separately
• Be aware of entry/exit requirements for your destination countries
• Consult your organization’s travel security policies if carrying work devices

Keep Your Operating System and Apps Updated

Security patches address newly discovered vulnerabilities that hackers actively exploit. Enable automatic updates to ensure you receive critical fixes immediately.

Android Update Settings:

• Navigate to Settings > System > System update
• Enable Automatic system updates
• Enable Download updates automatically when connected to Wi-Fi
• Check for updates manually if automatic updates don’t run

iOS Update Settings:

• Go to Settings > General > Software Update
• Tap Automatic Updates
• Enable both Download iOS Updates and Install iOS Updates
• Your device will update automatically overnight while charging

These updates often include patches for serious vulnerabilities. Google warned Android users about CVE-2024-53104, a critical kernel vulnerability requiring immediate patching.

App Update Best Practices:

App updates are equally important. OWASP Mobile Top 10 identifies outdated components as a major security risk.

• Google Play Store: Open Play Store > Profile icon > Settings > Network preferences > Enable Auto-update apps
• Apple App Store: Settings > App Store > Enable App Updates under Automatic Downloads
• Review app updates periodically to stay informed about changes
• Remove apps you no longer use to reduce security risks

Manage App Permissions and Privacy Settings

Apps frequently request more permissions than necessary. CISA recommends carefully reviewing what data each app can access.

Android Permission Management:

• Go to Settings > Privacy > Permission Manager
• Review permissions by category (Camera, Microphone, Location, Contacts, etc.)
• Tap each permission type to see which apps have access
• Change permissions to Ask every time or Deny for sensitive data
• Use one-time permissions that expire after closing the app (Android 11+)
• Review Special app access for elevated permissions

iOS Permission Management:

• Navigate to Settings > Privacy & Security
• Review each permission category (Location Services, Photos, Camera, Microphone, etc.)
• Tap individual apps to modify their access levels
• For location, choose While Using App instead of Always
• Enable Precise Location only when necessary
• Review Tracking settings and deny tracking requests

According to research, while iOS provides clearer permission prompts upfront, Android offers more granular control after installation.

Key Permissions to Monitor:

• Camera access: Only grant to legitimate photo/video apps and video calling services
• Microphone: Presents eavesdropping risks; deny unless essential for app functionality
• Location data: Enables constant tracking; use “While Using App” when possible
• Contacts: Contains sensitive personal information; limit to communication apps
• Phone: Can make calls and access call logs; be highly selective
• SMS/Messages: Can read and send texts; deny except for messaging apps

Implement Device Encryption and Lock Screen Security

Modern smartphones encrypt data by default, but verification is essential. Device encryption protects your information if your phone is lost or stolen.

Android Encryption:

• Android 10 and later: Encryption enabled automatically
• Verify status: Settings > Security > Encryption & credentials
• For older devices: Manually enable through Settings > Security > Encrypt device
• Ensure a strong lock screen password is set to activate encryption

iOS Encryption:

• Built-in hardware encryption through Secure Enclave chip
• Automatically activated when you set a passcode
• Biometric data and encryption keys stored separately from main processor
• Cannot be extracted even with sophisticated attacks

Lock Screen Security Settings:

• Set screen timeout to 30 seconds of inactivity maximum
• Disable lock screen notifications for sensitive apps (banking, email, messaging)
• Hide notification content until device is unlocked
• Disable Smart Lock features in high-security situations
• Require authentication immediately after screen turns off

Use Two-Factor Authentication Everywhere

Two-factor authentication requires two forms of identification, dramatically reducing unauthorized access even if passwords are compromised.

Recommended Authenticator Apps:

• Google Authenticator: Simple, reliable TOTP generator
• Microsoft Authenticator: Includes cloud backup and password manager
• Authy: Multi-device support with encrypted backups
• All generate time-based one-time passwords (TOTP) that change every 30 seconds
• More secure than SMS-based 2FA, which can be intercepted

Enable 2FA on Android:

1. Open your Google Account settings
2. Navigate to Security > 2-Step Verification
3. Tap Get Started
4. Verify your phone number
5. Choose your second verification method (authenticator app recommended)
6. Save backup codes in a secure location

Enable 2FA on iOS:

1. Open Settings
2. Tap your name at the top
3. Select Password & Security
4. Tap Turn On Two-Factor Authentication
5. Follow the on-screen instructions
6. Add a trusted phone number for verification

Accounts That Should Have 2FA:

The FTC recommends enabling 2FA on:

• Email accounts: Gateway to password resets for other services
• Banking and financial services: Protects your money
• Social media: Prevents account hijacking and impersonation
• Cloud storage: Secures your backed-up data and files
• Work accounts: Protects corporate data and communications
• Shopping accounts: Safeguards payment information

Protect Your Device from Physical Theft

Both platforms now offer advanced anti-theft features that activate automatically when your device is stolen.

Android 15 Theft Protection Features:

Android 15 introducedTheft Detection Lock, which uses AI and motion sensors to detect suspicious activity.

• Theft Detection Lock: Automatically locks screen if someone snatches and runs with your device
• Offline Device Lock: Locks screen after extended internet disconnection
• Remote Lock: Lock device from another device using just your phone number
• Setup: Settings > Google > All services > Personal & device safety > Theft Protection

iOS Stolen Device Protection:

iOS offersStolen Device Protection with location-aware security.

• Requires Face ID or Touch ID with no passcode fallback in unfamiliar locations
• Adds security delays for sensitive actions like changing Apple ID password
• Prevents disabling Find My iPhone without additional authentication
• Setup: Settings > Face ID & Passcode > Enable Stolen Device Protection

Device Tracking and Remote Management:

• Android: Enable Find My Device before loss occurs
  • Settings > Security > Find My Device
  • Allows remote location, lock, and wipe via android.com/find
• iOS: Enable Find My iPhone
  • Settings > [Your Name] > Find My > Find My iPhone
  • Enable both Find My iPhone and Find My network
  • Access via icloud.com/find from any browser
• Configure these features proactively—cannot be enabled remotely after theft

Secure Your Network Connections

Public Wi-Fi networks expose your data to interception. VPNs encrypt your internet traffic, preventing hackers from eavesdropping even on unsecured networks.

Why Use a VPN:

• Creates encrypted tunnel between your device and the internet
• Masks your IP address from websites and trackers
• Protects sensitive data on public Wi-Fi (coffee shops, airports, hotels)
• Essential when accessing banking apps or entering passwords publicly

VPN Setup:

• Android: Settings > Network & internet > VPN > Add VPN profile
• iOS: Settings > VPN > Add VPN Configuration
• Choose reputable providers with:
  • Strong encryption protocols (WireGuard or OpenVPN)
  • No-logging policies
  • Good privacy track record

VPN Services: Mini Reviews and Comparisons

Quick Comparison Table

Additional Network Security Measures:

CISA’s mobile communications guidance recommends:

• Use only end-to-end encrypted communications for sensitive conversations
• Prefer apps like Signal or WhatsApp that provide automatic encryption
• Disable automatic Wi-Fi connections to unknown networks
• Turn off Bluetooth when not in use to prevent unauthorized pairing
• Forget public Wi-Fi networks after use
• Verify network names before connecting (avoid fake hotspots)

Configure Secure Backup Solutions

Regular backups protect against data loss from theft, damage, or malware. However, backups must be secured properly to prevent unauthorized access.

Android Backup Configuration:

• Navigate to Settings > Google > Backup
• Enable Back up by Google One
• Set a strong backup password separate from your Google account password
• Enable encryption for backup data
• Choose what to back up (apps, photos, SMS, call history)
• Verify automatic backup schedule

iOS Backup Configuration:

• Go to Settings > [Your Name] > iCloud > iCloud Backup
• Enable iCloud Backup (automatic when charging and connected to Wi-Fi)
• For enhanced security, create encrypted local backups:
  • Connect to Mac or PC
  • Open Finder (Mac) or iTunes (PC)
  • Select device and choose Encrypt local backup
  • Set a strong backup password

Backup Security Best Practices:

• Protect cloud accounts with strong, unique passwords
• Enable two-factor authentication on cloud storage accounts
• Follow the 3-2-1 backup rule:
  • 3 copies of important data
  • 2 stored on different media types
  • 1 copy kept offsite
• Verify backups complete successfully
• Test restoration process periodically

Install Security Apps and Malware Protection

While iOS’s closed ecosystem provides inherent protection, Android’s open nature requires additional vigilance. Google Play Protect scans apps for malware automatically, but dedicated security apps offer enhanced protection.

Android Security:

• Verify Play Protect is active:
  • Open Google Play Store
  • Tap profile icon > Play Protect
  • Ensure “Scan apps with Play Protect” is enabled
• Play Protect scans over 100 billion apps daily for malicious behavior
• Consider additional security apps from:
  • Norton Mobile Security
  • McAfee Mobile Security
  • Bitdefender Mobile Security
• Features to look for: anti-phishing, web protection, app scanning

iOS Security:

• Benefits from Apple’s strict app review process and sandboxing
• Safari includes built-in protections against malicious websites
• iOS 18 introduces Advanced Tracking and Fingerprinting Protections
• Remain vigilant for scam websites and phishing attempts
• Use caution with links in emails and text messages

App Management Best Practices:

• Regularly review installed apps and remove unused ones
• Unused apps accumulate security vulnerabilities over time
• Check app reviews and developer credibility before installation
• Only download from official app stores (Google Play, Apple App Store)
• Verify app permissions match stated functionality
• Be suspicious of apps requesting excessive permissions

Practice Safe Browsing and Download Habits

Human behavior remains the weakest security link. Phishing attacks trick users into revealing passwords or installing malware regardless of technical protections.

Safe Browsing Practices:

• Verify website URLs before entering sensitive information
• Look for HTTPS connections (padlock icon) when shopping or banking
• Check for spelling errors in domain names (common phishing tactic)
• Be skeptical of unsolicited messages requesting personal information
• Legitimate companies never ask for passwords via email or text
• Hover over links to preview destinations before clicking

Android Download Safety:

• Avoid downloading apps from third-party sources
• Sideloading bypasses Google’s security checks
• If you must install from unknown sources:
  • Use antivirus to scan the APK file first
  • Verify the source’s reputation
  • Disable “Install unknown apps” permission immediately after
• Keep “Install unknown apps” disabled by default

iOS Safety Precautions:

• Avoid clicking “Trust” on certificate warnings
• Don’t connect to unfamiliar computers requesting trust
• Be cautious with public charging stations
• Use your own charging cable and power adapter to prevent “juice jacking”
• Juice jacking attacks install malware through compromised USB ports

Ongoing Security Awareness:

According to security experts, staying informed about emerging threats and maintaining security awareness is as important as technical configurations.

• Regularly review your security settings
• Adjust configurations as new threats emerge
• Stay informed about platform-specific vulnerabilities
• Follow security news from official sources
• Participate in security awareness training if available
• Share security knowledge with family and friends

Sources

• CISA Mobile Communications Best Practice Guidance
• Android’s Theft Protection Features
• Apple Stolen Device Protection
• OWASP Mobile Top 10
• 18 Android Security Settings That Will Strengthen Your Protection
• NSA Mobile Device Best Practices
• CISA App Permissions for Privacy and Security
• iOS vs Android App Permissions Privacy Comparison
• Microsoft Two-Factor Authentication Guide
• FTC Guide on Two-Factor Authentication
• McAfee: Why You Need a VPN on Your Smartphone
• Mobile Device Encryption Guide
• NCSC Backing Up Your Data Guide
• Android Security and Data Protection
• Apple Privacy Control Features