VaultNote implements comprehensive security measures to protect user data in an offline-first environment. All security features operate client-side with no external dependencies.

• Algorithm: AES-256-GCM (Galois/Counter Mode)
• Key Derivation: PBKDF2 with SHA-256
• Iterations: 600,000 (OWASP recommended minimum)
• IV Generation: Cryptographically secure random (12 bytes)
• Salt: 16 bytes, unique per encryption

• Authenticated encryption (prevents tampering)
• Unique IV for each encryption operation
• Secure key derivation from user password
• Memory-safe key handling (keys not extractable)

• Minimum 8 characters
• Stored as SHA-256 hash (never plaintext)
• Password verification uses constant-time comparison

• Maximum 5 failed attempts
• 15-minute lockout after max attempts
• Automatic lockout expiration

• Configurable session timeout (default: 30 minutes)
• Auto-lock on inactivity
• Activity monitoring (mouse, keyboard, scroll)
• Manual lock capability

• Whitelist-based tag filtering
• Attribute validation
• Style sanitization
• Event handler removal
• URL validation for links

• Block content length limits
• Null byte removal
• Control character filtering
• Prototype pollution prevention

• Protocol whitelist (http, https, mailto)
• Dangerous protocol blocking (javascript:, data:, etc.)
• Path traversal prevention
• Relative URL sanitization

• All external network requests blocked
• Only local connections allowed (localhost, 127.0.0.1, LAN)
• WebSocket restrictions (local only)
• Beacon API blocked
• Fetch API interception
• XMLHttpRequest interception

• Strict CSP headers
• Script source restrictions
• Style source restrictions
• Image source restrictions
• No external resource loading

• Prototype pollution protection
• Secure JSON parsing
• Data integrity verification
• Version tracking for migrations

• Optional password-protected encryption
• All sensitive data encrypted at rest
• Separate encryption keys per vault
• Secure key derivation

• Sensitive data overwritten with random data
• Memory zeroing after use
• Key material cleared from memory
• No persistent key storage

• Keys marked as non-extractable
• No key material in logs
• Secure random generation for all IDs
• No sensitive data in error messages

• Encryption enable/disable
• Vault lock/unlock
• Failed unlock attempts
• Network blocking
• XSS attempts
• Input validation failures
• Storage access
• Password changes

• In-memory only (not persisted)
• Maximum 1000 events
• Automatic rotation
• Event details and timestamps
• Blocked action tracking

• Overwrite with random data before deletion
• Multiple localStorage keys cleared
• Secure key removal
• Complete vault deletion

1. Identify all vault-related keys
2. Overwrite with random data
3. Remove from localStorage
4. Clear in-memory state
5. Reset security configuration

1. Use Strong Passwords

   • Minimum 8 characters
   • Mix of uppercase, lowercase, numbers, symbols
   • Unique password for vault

2. Enable Auto-Lock

   • Set appropriate session timeout
   • Lock manually when stepping away
   • Use auto-lock on inactivity

3. Regular Backups

   • Export encrypted backups
   • Store backups securely
   • Test backup restoration

4. Keep App Updated

   • Security improvements in updates
   • Bug fixes and patches
   • New security features

1. Input Validation

   • Always validate user input
   • Use inputValidation module
   • Sanitize before storage

2. Encryption

   • Use encryption module for sensitive data
   • Never store passwords in plaintext
   • Use secure random for IVs and salts

3. Network Security

   • Never make external requests
   • Use network isolation
   • Block all external connections

4. Error Handling

   • Don't expose sensitive data in errors
   • Log security events appropriately
   • Handle failures gracefully

• AES-256-GCM encryption
• PBKDF2 key derivation (600k iterations)
• Password protection with lockout
• Session timeout and auto-lock
• HTML/XSS sanitization
• URL validation
• Prototype pollution protection
• Network isolation
• Content Security Policy
• Secure random generation
• Memory protection
• Secure deletion
• Audit logging
• Input validation
• Rate limiting

1. XSS Attacks

   • HTML sanitization
   • Attribute filtering
   • Event handler removal

2. Prototype Pollution

   • JSON parsing protection
   • Object key filtering
   • Recursive sanitization

3. SQL Injection

   • Pattern detection
   • Query sanitization
   • Local database only

4. Command Injection

   • Character filtering
   • Pattern detection
   • Input validation

5. Brute Force

   • Rate limiting
   • Lockout mechanism
   • Failed attempt tracking

6. Data Exfiltration

   • Network isolation
   • No external requests
   • Local-only storage

7. Memory Attacks

   • Secure wiping
   • Non-extractable keys
   • Key material protection

1. Browser Security

   • Depends on browser security
   • Subject to browser vulnerabilities
   • localStorage limitations

2. Physical Access

   • Cannot protect against physical access
   • Device encryption recommended
   • OS-level security important

3. Malware

   • Cannot protect against keyloggers
   • Screen capture possible
   • Clipboard monitoring possible

Security is an ongoing process. Regular updates include:

• Security patches
• Algorithm improvements
• New threat mitigations
• Best practice updates

If you discover a security vulnerability:

1. Do not create a public issue
2. Contact the maintainers privately
3. Provide detailed information
4. Allow time for fix before disclosure

VaultNote security features support:

• Data privacy requirements
• Offline-first architecture
• Zero-trust principles
• Defense in depth
• Principle of least privilege