Data Minimization and Privacy

Data Minimization and Privacy

Beyond encryption, limiting data collection and retention enhances security.

// iOS - Privacy-focused data handling
class PrivacyManager {
    
    // Automatic data expiration
    func storeTemporaryData(_ data: Data, key: String, expirationMinutes: Int) {
        let expirationDate = Date().addingTimeInterval(TimeInterval(expirationMinutes * 60))
        
        let wrapper = ExpiringDataWrapper(
            data: data,
            expirationDate: expirationDate
        )
        
        // Store with expiration
        UserDefaults.standard.set(
            try? JSONEncoder().encode(wrapper),
            forKey: key
        )
        
        // Schedule cleanup
        scheduleCleanup(for: key, at: expirationDate)
    }
    
    // Data anonymization
    func anonymizeUserData(_ userData: UserData) -> AnonymizedData {
        return AnonymizedData(
            id: generateAnonymousID(),
            ageRange: categorizeAge(userData.age),
            region: generalizeLocation(userData.location),
            preferences: userData.preferences
        )
    }
    
    // Secure data deletion
    func securelyDeleteData(at url: URL) throws {
        let data = try Data(contentsOf: url)
        
        // Overwrite with random data multiple times
        for _ in 0..<3 {
            let randomData = generateRandomData(size: data.count)
            try randomData.write(to: url)
        }
        
        // Delete file
        try FileManager.default.removeItem(at: url)
    }
}

struct ExpiringDataWrapper: Codable {
    let data: Data
    let expirationDate: Date
    
    var isExpired: Bool {
        return Date() > expirationDate
    }
}

Secure data storage and encryption form the foundation of mobile application security. By implementing platform-specific security features, using proven encryption algorithms, and following key management best practices, developers can protect sensitive data throughout its lifecycle. Remember that security is not just about using encryption—it's about implementing defense-in-depth strategies that protect data at every level. The next chapter explores network security and API protection to ensure data remains secure during transmission.## Network Security and API Protection

Mobile applications are inherently connected, relying on network communication for core functionality. This connectivity, while enabling rich features, also exposes applications to network-based attacks. This chapter explores comprehensive strategies for securing network communications, protecting APIs, and ensuring data integrity during transmission between mobile applications and backend services.