diff --git a/ROADMAP.md b/ROADMAP.md index bed53b0..db9dec3 100644 --- a/ROADMAP.md +++ b/ROADMAP.md @@ -101,11 +101,43 @@ This roadmap outlines the development priorities and strategic direction for Lit --- -## 🚀 Phase 3: Feature Enhancements (Q1 2026 - January-March) +## 🚀 Phase 3: Feature Enhancements (Q4 2025 - Q1 2026) + +### Security & Privacy Features + +#### 1. 🔒 TeleBot Channel Lock & PIN Protection [HIGH PRIORITY] +- **Status**: 📋 Documented - Ready for Implementation +- **Priority**: HIGH - Privacy & Security Enhancement +- **Location**: `docs/CHANNEL_LOCK_DESIGN.md` +- **Description**: Complete channel lock system with 4-digit PIN protection +- **Features**: + - Single security gate protecting all bot functionality + - 4-digit PIN with PBKDF2 hashing (100,000 iterations) + - Auto-lock modes (Manual, On Main Menu, Inactivity, On Exit, Always) + - Brute force protection (3 attempts → 5 min lockout) + - Screenshot-safe locked state (no data visible) + - Backward compatible (Guest mode for users without PIN) +- **Benefits**: + - ✅ Enterprise-grade privacy protection + - ✅ Shared device safety + - ✅ Mobile banking UX pattern + - ✅ GDPR compliance enhancement + - ✅ Zero data loss (preserved during lock) +- **Implementation Estimate**: 2-3 hours core + 1-2 hours UX polish +- **Timeline**: October 2025 +- **Success Metrics**: + - 60% user adoption within 30 days + - < 0.1% lockout rate + - > 90% user satisfaction +- **Future Enhancements**: + - Biometric unlock (Telegram WebApp API) + - 2FA/TOTP support + - Hardware security key integration + - Zero-knowledge encryption ### Shipping & Logistics -#### 1. Royal Mail Integration +#### 2. Royal Mail Integration - API integration for label generation - Tracking number management - Automated shipping calculations @@ -113,7 +145,7 @@ This roadmap outlines the development priorities and strategic direction for Lit - **Timeline**: January 2026 - **Status**: 🔴 PLANNED -#### 2. Multi-Carrier Support +#### 3. Multi-Carrier Support - Abstract shipping provider interface - Support for DHL, FedEx, UPS - Shipping rule engine @@ -122,7 +154,7 @@ This roadmap outlines the development priorities and strategic direction for Lit ### Communication & Notifications -#### 3. Email Notification System +#### 4. Email Notification System - Order confirmation emails - Shipping notifications - Payment status updates @@ -130,7 +162,7 @@ This roadmap outlines the development priorities and strategic direction for Lit - **Timeline**: January 2026 - **Status**: 🔴 PLANNED -#### 4. Enhanced Telegram Bot Features +#### 5. Enhanced Telegram Bot Features - Rich media product browsing - Voice message support - Automated customer support responses @@ -140,7 +172,7 @@ This roadmap outlines the development priorities and strategic direction for Lit ### Analytics & Reporting -#### 5. Advanced Analytics Dashboard +#### 6. Advanced Analytics Dashboard - Sales trends and forecasting - Customer behavior analytics - Product performance metrics @@ -148,7 +180,7 @@ This roadmap outlines the development priorities and strategic direction for Lit - **Timeline**: February 2026 - **Status**: 🔴 PLANNED -#### 6. Financial Reporting +#### 7. Financial Reporting - Automated tax calculations - Multi-currency reconciliation - Export to accounting software diff --git a/docs/CHANNEL_LOCK_DESIGN.md b/docs/CHANNEL_LOCK_DESIGN.md new file mode 100644 index 0000000..65200ab --- /dev/null +++ b/docs/CHANNEL_LOCK_DESIGN.md @@ -0,0 +1,733 @@ +# TeleBot Channel Lock & PIN Protection Design + +**Status**: 📋 Documented - Ready for Implementation +**Priority**: 🔒 HIGH - Security & Privacy Enhancement +**Target**: Q4 2025 (October 2025) +**Estimated Implementation**: 2-3 hours core functionality + 1-2 hours UX polish +**Last Updated**: October 6, 2025 + +--- + +## Executive Summary + +Complete channel lock system for TeleBot that provides enterprise-grade privacy protection through a 4-digit PIN. When enabled, the entire Telegram conversation is locked with a single security gate, requiring PIN entry to access any functionality beyond the unlock screen. + +### Key Benefits + +✅ **Single Security Boundary** - One gate protects all features, not selective locks +✅ **Screenshot Safe** - Locked screen shows no sensitive data +✅ **Shared Device Safe** - Complete protection for shared/public devices +✅ **Mobile Banking UX** - Familiar pattern from banking/crypto wallet apps +✅ **No Data Loss** - All data preserved in session, just visibility controlled +✅ **Privacy by Design** - User controls when and how data is visible +✅ **Simple Implementation** - Early gate check, minimal code complexity + +--- + +## Architecture Overview + +### Core Concept + +``` +┌─────────────────────────────────────────┐ +│ ALL TELEGRAM UPDATES │ +│ (Messages, Callbacks, Commands) │ +└──────────────────â”Ŧ──────────────────────┘ + │ + â–ŧ + ┌─────────────────────┐ + │ SECURITY GATE │ + │ Is session locked? │ + └─────────â”Ŧ───────────┘ + │ + ┌─────────┴──────────┐ + │ │ + â–ŧ â–ŧ + 🔒 LOCKED ✅ UNLOCKED + Show unlock Process normally + screen only (full features) +``` + +### State Model + +```csharp +public enum SessionState +{ + Guest, // No PIN set, full access (backward compatible with existing users) + Unlocked, // PIN set, currently unlocked (full access) + Locked // PIN set, currently locked (GATE BLOCKS ALL ACTIONS) +} +``` + +--- + +## User Experience Design + +### 1. First-Time Setup (Optional) + +``` +┌─────────────────────────────────────┐ +│ 🔐 Secure Your Orders │ +├─────────────────────────────────────┤ +│ Protect your personal information │ +│ and order history with a 4-digit │ +│ PIN code. │ +│ │ +│ â€ĸ Lock chat automatically │ +│ â€ĸ Protect payment details │ +│ â€ĸ Secure order history │ +│ │ +│ [✅ Set Up PIN] [⏭ī¸ Skip] │ +└─────────────────────────────────────┘ +``` + +**Design Decisions:** +- Completely optional - existing users continue with Guest mode +- Clear value proposition - explain what PIN protects +- No friction - skip option for users who don't need it +- Re-prompt after 3 orders or 7 days (gentle nudge) + +### 2. PIN Setup Flow + +``` +Step 1: Enter New PIN +┌─────────────────────────────────────┐ +│ đŸ”ĸ Create Your PIN │ +├─────────────────────────────────────┤ +│ PIN: ● ● ● ● │ +│ │ +│ [1] [2] [3] │ +│ [4] [5] [6] │ +│ [7] [8] [9] │ +│ [âŦ…ī¸ Clear] [0] [✅ Next] │ +└─────────────────────────────────────┘ + +Step 2: Confirm PIN +┌─────────────────────────────────────┐ +│ đŸ”ĸ Confirm Your PIN │ +├─────────────────────────────────────┤ +│ Enter your PIN again to confirm │ +│ │ +│ PIN: ● ● ● ● │ +│ │ +│ [Numeric keypad as above] │ +└─────────────────────────────────────┘ + +Step 3: Success +┌─────────────────────────────────────┐ +│ ✅ PIN Protection Enabled │ +├─────────────────────────────────────┤ +│ Your chat is now protected with │ +│ a secure PIN. │ +│ │ +│ Auto-lock: 🏠 On Main Menu │ +│ │ +│ [⚙ī¸ Settings] [🏠 Main Menu] │ +└─────────────────────────────────────┘ +``` + +### 3. Locked State (Primary UX) + +``` +┌─────────────────────────────────────┐ +│ 🔒 Channel Locked │ +├─────────────────────────────────────┤ +│ Enter your 4-digit PIN to continue │ +│ │ +│ Locked at: 14:32 │ +│ │ +│ [🔓 Unlock] │ +└─────────────────────────────────────┘ +``` + +**Important:** This is the ONLY message shown when locked. No other features accessible. + +### 4. Unlock Flow + +``` +┌─────────────────────────────────────┐ +│ đŸ”ĸ Enter PIN │ +├─────────────────────────────────────┤ +│ PIN: ● ● ○ ○ │ +│ │ +│ Attempts remaining: 3 │ +│ │ +│ [1] [2] [3] │ +│ [4] [5] [6] │ +│ [7] [8] [9] │ +│ [âŦ…ī¸ Clear] [0] [✅ Submit] │ +└─────────────────────────────────────┘ + +After Successful Unlock: +┌─────────────────────────────────────┐ +│ ✅ Unlocked │ +├─────────────────────────────────────┤ +│ Welcome back! │ +│ │ +│ [Returns to normal menu] │ +└─────────────────────────────────────┘ + +Failed Attempt: +┌─────────────────────────────────────┐ +│ ❌ Incorrect PIN │ +├─────────────────────────────────────┤ +│ PIN: ○ ○ ○ ○ │ +│ │ +│ Attempts remaining: 2 │ +│ ⚠ī¸ Account locks after 3 failures │ +│ │ +│ [Numeric keypad] │ +└─────────────────────────────────────┘ + +Account Locked (after 3 failures): +┌─────────────────────────────────────┐ +│ đŸšĢ Account Temporarily Locked │ +├─────────────────────────────────────┤ +│ Too many failed attempts. │ +│ │ +│ Try again in: 5 minutes │ +│ │ +│ [❓ Forgot PIN?] │ +└─────────────────────────────────────┘ +``` + +### 5. Auto-Lock Modes + +``` +⚙ī¸ Security Settings +├── 🔐 PIN Protection: ✅ Enabled +│ ├── 📌 Change PIN +│ └── ❌ Disable PIN (requires current PIN) +│ +├── 🔒 Auto-Lock: 🏠 On Main Menu â–ŧ +│ │ +│ ├── ✋ Manual Only +│ │ └── Lock only when "🔒 Lock" button clicked +│ │ +│ ├── 🏠 On Main Menu (Recommended) +│ │ └── Auto-lock when returning to main menu +│ │ +│ ├── ⏰ After Inactivity +│ │ └── Lock after [30 â–ŧ] minutes idle +│ │ +│ ├── đŸšĒ On Exit +│ │ └── Lock on any "back to menu" action +│ │ +│ └── 🔐 Always (Paranoid Mode) +│ └── Lock after EVERY single action +│ +├── 🗑ī¸ Clear All Data (requires PIN) +│ └── Permanently delete order history, cart, settings +│ +└── ℹī¸ Security Info + ├── PIN Last Changed: Oct 6, 2025 + ├── Last Locked: 2 hours ago + └── Failed Attempts Today: 0 +``` + +--- + +## Technical Implementation + +### 1. Database Schema Changes + +```csharp +public class UserSession +{ + // Existing fields... + public Guid Id { get; set; } + public long TelegramUserId { get; set; } + public Cart Cart { get; set; } + public List Conversation { get; set; } + + // NEW: Security & Lock State + public SessionState State { get; set; } = SessionState.Guest; + public string? PinHash { get; set; } // PBKDF2 hash, null = no PIN + public DateTime? LastActivityAt { get; set; } + public DateTime? LockedAt { get; set; } + public int FailedPinAttempts { get; set; } + public DateTime? LockoutUntil { get; set; } + public SecuritySettings Security { get; set; } = new(); + public string? PinEntry { get; set; } // Temporary, in-memory only (not persisted) +} + +public class SecuritySettings +{ + public bool PinEnabled { get; set; } + public AutoLockMode AutoLock { get; set; } = AutoLockMode.OnMainMenu; + public int AutoLockMinutes { get; set; } = 30; + public DateTime? PinCreatedAt { get; set; } + public DateTime? PinLastChangedAt { get; set; } +} + +public enum AutoLockMode +{ + Manual, // Only lock when user clicks button + OnMainMenu, // Lock when returning to main menu (default) + OnInactivity, // Lock after X minutes idle + OnExit, // Lock on any "back to menu" action + Always // Lock after every single action (paranoid mode) +} +``` + +### 2. Security Gate Implementation + +```csharp +// CallbackHandler.cs - Primary entry point for all user interactions +public async Task Handle(ITelegramBotClient bot, CallbackQuery callbackQuery, CancellationToken ct) +{ + var telegramUser = callbackQuery.From; + var session = await _sessionManager.GetOrCreateSessionAsync(telegramUser.Id); + + // UPDATE ACTIVITY TIMESTAMP + session.LastActivityAt = DateTime.UtcNow; + + // SECURITY GATE - Check lock state BEFORE any other processing + if (session.State == SessionState.Locked && !IsUnlockAction(callbackQuery.Data)) + { + await ShowUnlockScreen(bot, callbackQuery); + return; // STOP ALL PROCESSING - gate closed + } + + // Check if account is in lockout period + if (session.LockoutUntil.HasValue && DateTime.UtcNow < session.LockoutUntil.Value) + { + await ShowLockoutScreen(bot, callbackQuery, session.LockoutUntil.Value); + return; + } + + // If unlocked or this is unlock action, continue normal flow + await ProcessCallback(bot, callbackQuery, session); + + // CHECK AUTO-LOCK CONDITIONS after action completes + await CheckAndApplyAutoLock(session); +} + +private bool IsUnlockAction(string? callbackData) +{ + return callbackData?.StartsWith("unlock") == true || + callbackData?.StartsWith("pin_entry:") == true || + callbackData == "show_pin_pad" || + callbackData == "pin_clear" || + callbackData?.StartsWith("pin_digit:") == true; +} +``` + +### 3. PIN Management + +```csharp +// PIN Hashing (secure storage) +public string HashPin(string pin) +{ + using var rfc2898 = new Rfc2898DeriveBytes( + pin, + saltSize: 32, + iterations: 100_000, + HashAlgorithmName.SHA256 + ); + + var hash = Convert.ToBase64String(rfc2898.GetBytes(32)); + var salt = Convert.ToBase64String(rfc2898.Salt); + + return $"{salt}:{hash}"; // Store both salt and hash +} + +// PIN Verification +public bool VerifyPin(string enteredPin, string storedHash) +{ + var parts = storedHash.Split(':'); + if (parts.Length != 2) return false; + + var salt = Convert.FromBase64String(parts[0]); + var hash = Convert.FromBase64String(parts[1]); + + using var rfc2898 = new Rfc2898DeriveBytes( + enteredPin, + salt, + iterations: 100_000, + HashAlgorithmName.SHA256 + ); + + var enteredHash = rfc2898.GetBytes(32); + return CryptographicOperations.FixedTimeEquals(hash, enteredHash); +} + +// PIN Entry Handling +private async Task HandlePinDigit(ITelegramBotClient bot, CallbackQuery query, UserSession session, string digit) +{ + if (session.PinEntry == null) + session.PinEntry = ""; + + if (digit == "clear") + { + session.PinEntry = ""; + } + else if (digit == "submit" && session.PinEntry.Length == 4) + { + await HandlePinSubmit(bot, query, session); + return; + } + else if (session.PinEntry.Length < 4) + { + session.PinEntry += digit; + } + + // Refresh PIN pad with updated dots + await ShowPinPad(bot, query, session); +} + +private async Task HandlePinSubmit(ITelegramBotClient bot, CallbackQuery query, UserSession session) +{ + if (VerifyPin(session.PinEntry, session.PinHash!)) + { + // SUCCESS + session.State = SessionState.Unlocked; + session.FailedPinAttempts = 0; + session.PinEntry = null; + + await bot.EditMessageTextAsync( + query.Message!.Chat.Id, + query.Message.MessageId, + "✅ *Unlocked*\n\nWelcome back!", + parseMode: ParseMode.Markdown, + replyMarkup: MenuBuilder.MainMenu() + ); + } + else + { + // FAILURE + session.FailedPinAttempts++; + session.PinEntry = null; + + if (session.FailedPinAttempts >= 3) + { + // LOCKOUT + session.LockoutUntil = DateTime.UtcNow.AddMinutes(5); + await ShowLockoutScreen(bot, query, session.LockoutUntil.Value); + } + else + { + await ShowPinPad(bot, query, session, isError: true); + } + } + + await _sessionManager.SaveSessionAsync(session); +} +``` + +### 4. Auto-Lock Logic + +```csharp +private async Task CheckAndApplyAutoLock(UserSession session) +{ + // Don't lock if PIN not enabled or already locked + if (!session.Security.PinEnabled || session.State == SessionState.Locked) + return; + + bool shouldLock = session.Security.AutoLock switch + { + AutoLockMode.Manual => false, // Never auto-lock + + AutoLockMode.OnMainMenu => + session.CurrentMenu == "main" || session.LastAction == "menu", + + AutoLockMode.OnInactivity => + (DateTime.UtcNow - session.LastActivityAt.GetValueOrDefault()).TotalMinutes + >= session.Security.AutoLockMinutes, + + AutoLockMode.OnExit => + session.CurrentMenu == "main" || + session.LastAction == "back" || + session.LastAction == "menu", + + AutoLockMode.Always => true, // Lock after every action + + _ => false + }; + + if (shouldLock) + { + session.State = SessionState.Locked; + session.LockedAt = DateTime.UtcNow; + session.PinEntry = null; // Clear any temporary PIN entry + await _sessionManager.SaveSessionAsync(session); + + _logger.LogInformation( + "Session {SessionId} auto-locked (mode: {Mode})", + session.Id, + session.Security.AutoLock + ); + } +} +``` + +### 5. UI Components + +```csharp +// MenuBuilder.cs additions + +public InlineKeyboardMarkup UnlockScreen() +{ + return new InlineKeyboardMarkup(new[] + { + new[] + { + InlineKeyboardButton.WithCallbackData("🔓 Unlock", "show_pin_pad") + } + }); +} + +public InlineKeyboardMarkup PinPad(UserSession session, bool isError = false) +{ + var maskLength = session.PinEntry?.Length ?? 0; + var mask = new string('●', maskLength) + new string('○', 4 - maskLength); + + return new InlineKeyboardMarkup(new[] + { + new[] + { + InlineKeyboardButton.WithCallbackData("1", "pin_digit:1"), + InlineKeyboardButton.WithCallbackData("2", "pin_digit:2"), + InlineKeyboardButton.WithCallbackData("3", "pin_digit:3") + }, + new[] + { + InlineKeyboardButton.WithCallbackData("4", "pin_digit:4"), + InlineKeyboardButton.WithCallbackData("5", "pin_digit:5"), + InlineKeyboardButton.WithCallbackData("6", "pin_digit:6") + }, + new[] + { + InlineKeyboardButton.WithCallbackData("7", "pin_digit:7"), + InlineKeyboardButton.WithCallbackData("8", "pin_digit:8"), + InlineKeyboardButton.WithCallbackData("9", "pin_digit:9") + }, + new[] + { + InlineKeyboardButton.WithCallbackData("âŦ…ī¸ Clear", "pin_clear"), + InlineKeyboardButton.WithCallbackData("0", "pin_digit:0"), + InlineKeyboardButton.WithCallbackData("✅ Submit", "pin_submit") + } + }); +} + +// Add lock button to main menu when PIN enabled +public InlineKeyboardMarkup MainMenu(UserSession? session = null) +{ + var buttons = new List + { + // ... existing menu items + }; + + // Add lock button if PIN is enabled + if (session?.Security.PinEnabled == true && session.State == SessionState.Unlocked) + { + buttons.Add(new[] + { + InlineKeyboardButton.WithCallbackData("🔒 Lock Chat", "lock_channel") + }); + } + + return new InlineKeyboardMarkup(buttons); +} +``` + +--- + +## Security Considerations + +### 1. PIN Storage +- ✅ PBKDF2 with 100,000 iterations (OWASP recommended) +- ✅ 32-byte random salt per PIN +- ✅ SHA-256 hash algorithm +- ✅ Constant-time comparison (prevents timing attacks) +- ❌ **Never** store PIN in plaintext + +### 2. Brute Force Protection +- ✅ 3 attempts before 5-minute lockout +- ✅ Progressive lockout (future: 5min → 15min → 1hr → 24hr) +- ✅ Failed attempt logging for audit trail +- ✅ Rate limiting on unlock endpoint + +### 3. Session Security +- ✅ PinEntry stored in memory only, never persisted to database +- ✅ Auto-clear PinEntry on lock/unlock/failure +- ✅ Session state synchronized across all interactions +- ✅ Activity timestamp updated on every interaction + +### 4. Data Protection +- ✅ All sensitive data (orders, payments, addresses) hidden when locked +- ✅ No data exposed in locked state messages +- ✅ Session data preserved but inaccessible +- ✅ Optional "Clear All Data" requires PIN verification + +--- + +## Migration & Backward Compatibility + +### Existing Users (Guest Mode) +- No disruption - continue using bot without PIN +- Optional prompt after 3 orders or 7 days: "Would you like to secure your orders with a PIN?" +- Can enable PIN anytime from Settings menu + +### Database Migration +```sql +-- Add new columns to UserSessions table +ALTER TABLE UserSessions ADD COLUMN State INTEGER DEFAULT 0; -- 0 = Guest +ALTER TABLE UserSessions ADD COLUMN PinHash TEXT NULL; +ALTER TABLE UserSessions ADD COLUMN LastActivityAt TEXT NULL; +ALTER TABLE UserSessions ADD COLUMN LockedAt TEXT NULL; +ALTER TABLE UserSessions ADD COLUMN FailedPinAttempts INTEGER DEFAULT 0; +ALTER TABLE UserSessions ADD COLUMN LockoutUntil TEXT NULL; +ALTER TABLE UserSessions ADD COLUMN SecuritySettings TEXT NULL; -- JSON + +-- Add indexes for performance +CREATE INDEX IX_UserSessions_State ON UserSessions(State); +CREATE INDEX IX_UserSessions_LockoutUntil ON UserSessions(LockoutUntil); +``` + +--- + +## Testing Strategy + +### Unit Tests +- ✅ PIN hashing and verification +- ✅ Auto-lock mode logic +- ✅ Lockout calculation +- ✅ PIN entry validation (4 digits only) + +### Integration Tests +- ✅ Full unlock flow (locked → pin entry → unlocked) +- ✅ Failed attempt lockout enforcement +- ✅ Auto-lock triggers (menu, inactivity, exit) +- ✅ State transitions (Guest → Unlocked → Locked) + +### E2E Tests (Playwright) +- ✅ First-time PIN setup flow +- ✅ Lock and unlock via menu +- ✅ Auto-lock on main menu return +- ✅ Failed attempts and lockout +- ✅ PIN change workflow +- ✅ Disable PIN and return to Guest mode + +--- + +## Implementation Checklist + +### Phase 1: Core Functionality (2-3 hours) +- [ ] Add `SessionState`, `PinHash`, security fields to `UserSession` model +- [ ] Create database migration for new columns +- [ ] Implement `HashPin()` and `VerifyPin()` methods +- [ ] Add security gate at top of `CallbackHandler.Handle()` +- [ ] Create `ShowUnlockScreen()` method +- [ ] Build PIN pad UI in `MenuBuilder.PinPad()` +- [ ] Implement `HandlePinDigit()` and `HandlePinSubmit()` +- [ ] Add lockout logic (3 attempts → 5 min timeout) +- [ ] Implement manual lock button in main menu + +### Phase 2: Auto-Lock (1 hour) +- [ ] Create `CheckAndApplyAutoLock()` method +- [ ] Implement all 5 auto-lock modes +- [ ] Add activity timestamp tracking +- [ ] Test auto-lock triggers + +### Phase 3: Settings & Management (1 hour) +- [ ] Create Security Settings menu +- [ ] Implement PIN setup flow (new users) +- [ ] Implement Change PIN flow +- [ ] Implement Disable PIN flow (requires current PIN) +- [ ] Add auto-lock mode selector +- [ ] Add "Clear All Data" with PIN verification + +### Phase 4: UX Polish (1-2 hours) +- [ ] Add first-time setup prompt (optional, after 3 orders) +- [ ] Improve error messages and feedback +- [ ] Add security info display (last locked, failed attempts) +- [ ] Add countdown timer for lockout screen +- [ ] Implement "Forgot PIN?" recovery flow (contact support) +- [ ] Add haptic/visual feedback for PIN entry + +### Phase 5: Testing & Deployment (1 hour) +- [ ] Write unit tests for PIN security +- [ ] Write integration tests for lock flows +- [ ] Manual E2E testing on Telegram +- [ ] Security review (penetration testing) +- [ ] Deploy to staging environment +- [ ] User acceptance testing +- [ ] Deploy to production with feature flag + +--- + +## Future Enhancements + +### Short Term (Q1 2026) +- **Biometric Unlock**: Support Telegram's WebApp biometric API +- **PIN Complexity**: Option for 6-digit PIN or alphanumeric password +- **Session Management**: "Lock all devices" from any session +- **Audit Log**: View all unlock events and failed attempts + +### Medium Term (Q2 2026) +- **2FA Support**: Optional TOTP/authenticator app second factor +- **Trusted Devices**: Remember devices, require PIN only on new devices +- **Emergency Contacts**: Designate trusted contact for PIN recovery +- **Secure Backup**: Encrypted backup of order history with recovery phrase + +### Long Term (Q3-Q4 2026) +- **Hardware Security**: Support for hardware security keys (YubiKey, etc.) +- **Zero-Knowledge Encryption**: End-to-end encrypted order data +- **Multi-Account**: Separate PINs for business vs personal shopping +- **Compliance**: FIPS 140-2 certification for payment card industry + +--- + +## Success Metrics + +### Security Metrics +- ✅ Zero unauthorized access incidents +- ✅ < 0.1% lockout rate (balance security vs UX) +- ✅ 100% PIN hash security (PBKDF2 with strong parameters) + +### User Adoption +- đŸŽ¯ Target: 60% of active users enable PIN within 30 days +- đŸŽ¯ Target: < 5% disable PIN after enabling +- đŸŽ¯ Target: > 90% user satisfaction with lock/unlock UX + +### Performance +- ✅ < 100ms PIN verification time +- ✅ < 500ms lock/unlock state transition +- ✅ Zero impact on unlocked session performance + +--- + +## Open Questions + +1. **Forgot PIN Flow**: Contact support vs security questions vs recovery phrase? + - **Recommendation**: Contact support with identity verification (Telegram username + recent order ID) + +2. **PIN Complexity**: Force 4 digits or allow stronger PINs? + - **Recommendation**: Default 4 digits, optional 6-digit or alphanumeric in settings + +3. **Session Expiry**: Should locked sessions expire and clear data after X days? + - **Recommendation**: 90-day expiry with warning email/notification at 80 days + +4. **Multi-Device**: If user has bot open on phone and desktop, lock both? + - **Recommendation**: Yes, state is server-side, lock applies to all clients + +5. **PIN Recovery**: Allow self-service PIN reset via email? + - **Recommendation**: Phase 1 = support only, Phase 2 = email with order verification + +--- + +## References + +- [OWASP Password Storage Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html) +- [Telegram Bot API Security Best Practices](https://core.telegram.org/bots/security) +- [NIST Digital Identity Guidelines](https://pages.nist.gov/800-63-3/) +- [PBKDF2 Implementation Guide](https://cryptobook.nakov.com/mac-and-key-derivation/pbkdf2) + +--- + +**Document Version**: 1.0 +**Author**: SilverLabs Development Team +**Review Date**: October 6, 2025 +**Next Review**: November 6, 2025 (post-implementation)