# Use Case 2.3 Unlock the app

## Overview

| Aspect                       | Description                                                                                                                                                                                                                                                                                                                   |
|------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Summary**                  | The user unlocks the app either by using biometrics or entering a PIN, with fallback options including PIN recovery or wallet deletion if access fails.                                                                                                                                                                       |
| **Goal**                     | Unlocking the app.                                                                                                                                                                                                                                                                                                            |
| **Preconditions**            | *None*                                                                                                                                                                                                                                                                                                                        |
| **Postconditions**           | *None*                                                                                                                                                                                                                                                                                                                        |
| **Triggered by**             | <ul><li>User completes [UC1.2 Open the app](UC1.2_OpenTheApp.md)</li></ul>                                                                                                                                                                                                                                                    |
| **Additional Documentation** | *None*                                                                                                                                                                                                                                                                                                                        |
| **Possible errors**          | <ul><li>No internet</li><li>Server unreachable</li></ul>                                                                                                                                                                                                                                                                      |
| **Logical Test Cases**       | <ul><li>[LTC47 Unlock app with correct PIN](../logical-test-cases.md#ltc76)</li><li>[LTC48 Unlock app with biometric](../logical-test-cases.md#ltc77)</li><li>[LTC49 Unlock app with invalid biometric](../logical-test-cases.md#ltc49)</li><li>[LTC50 Unlock app with invalid PIN](../logical-test-cases.md#ltc50)</li></ul> |

---

## Flow

| #       | Description                                                                                                                                                        | Next                                                                    |
| ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------------- |
| **1**   | **PRIMARY SCENARIO**                                                                                                                                               |                                                                         |
| **1.1** | **System determines whether biometrics are enabled**<ul><li>Duration: 0.0 - 0.1 seconds</li></ul>                                                                  |                                                                         |
| 1.1a    | Case: Biometrics are enabled                                                                                                                                       | 2                                                                       |
| 1.1b    | Case: Biometrics are not enabled                                                                                                                                   | 1.2                                                                     |
| **1.2** | **System scans biometrics**                                                                                                                                        |                                                                         |
| 1.2a    | Case: Valid biometric                                                                                                                                              | Go to: [UC7.1 Show all available cards](UC7.1_ShowAllAvailableCards.md) |
| 1.2b    | Case: Invalid biometric (first time iOS)                                                                                                                           | 2                                                                       |
| 1.2c    | Case: Invalid biometric (second time iOS)                                                                                                                          | 3                                                                       |
| 1.2d    | Case: Invalid biometric (first till fourth time Android)                                                                                                           | 4                                                                       |
| **1.3** | **System shows screen 'Open app with PIN'**<ul><li>Message: Open with your PIN</li><li>Input: 6 digits (0-9) PIN field</li><li>Actions: Info, Forgot Pin</li></ul> |                                                                         |
| 1.3a    | User enters PIN                                                                                                                                                    | 1.4                                                                     |
| 1.3b    | User selects Forgot PIN                                                                                                                                            | 6                                                                       |
| 1.3c    | User selects Info                                                                                                                                                  | Go to: [UC9.2 Get app information](UC9.2_GetAppInformation.md)          |
| **1.4** | **System executes partial flow [PF2.8 Validate PIN](../partial-flows/PF2.8_ValidatePin.md)**                                                                                      |                                                                         |
| 1.4a    | Result: Confirm                                                                                                                                                    | 1.5                                                                     |
| 1.4b    | Result: Retry                                                                                                                                                      | 1.3                                                                     |
| 1.4c    | Result: Back                                                                                                                                                       | Back                                                                    |
| **1.5** | **System determines whether user has obtained PID**<ul><li>Duration: 0.0 - 0.1 seconds</li></ul>                                                                   |                                                                         |
| 1.5a    | Case: User has obtained PID                                                                                                                                        | 1.6                                                                     |
| 1.5b    | Case: User has not obtained PID                                                                                                                                    | Go to: [UC3.1 Obtain PID](UC3.1_ObtainPidFromProvider.md)               |
| **1.6** | **System executes partial flow [PF2.7 Resolve a universal link](../partial-flows/PF2.7_ResolveUniversalLink.md)**                                                                 |                                                                         |
| 1.6a    | Result: No (valid) universal link                                                                                                                                  | 1.7                                                                     |
| **1.7** | **System determines whether app was shutdown before unlocking**                                                                                                    |                                                                         |
| 1.7a    | Case: App was active (iOS: resume, Android: hot start)                                                                                                             | Resume<sup>1</sup>                                                      |
| 1.7b    | Case: App was shutdown (iOS: launch, Android: cold or warm start)                                                                                                  | Go to: [UC7.1 Show all available cards](UC7.1_ShowAllAvailableCards.md) |
| **2**   | **WHEN BIOMETRIC IS INVALID, FIRST TIME IOS**                                                                                                                      |                                                                         |
| **2.1** | **System displays prompt 'Biometric not recognized'**<ul><li>Actions: Try again, Close</li></ul>                                                                   |                                                                         |
| 2.1a    | User selects Close                                                                                                                                                 | 1.3                                                                     |
| 2.1b    | User selects Try again                                                                                                                                             | 2.1                                                                     |
| **3**   | **WHEN BIOMETRIC IS INVALID, SECOND TIME IOS**                                                                                                                     |                                                                         |
| **3.1** | **System displays prompt 'Biometric not recognized enter your PIN'**<ul><li>Actions: Enter Password, Cancel</li></ul>                                              |                                                                         |
| 3.1a    | User selects Enter Password                                                                                                                                        | 1.3                                                                     |
| 3.1b    | User selects Cancel                                                                                                                                                | 1.3                                                                     |
| **4**   | **WHEN BIOMETRIC IS INVALID, FIRST TIME ANDROID**                                                                                                                  |                                                                         |
| **4.1** | **System displays message 'Biometric not recognized'**<ul><li>Actions: Try again, Close</li></ul>                                                                  |                                                                         |
| 4.1a    | User selects Close                                                                                                                                                 | 1.3                                                                     |
| 4.1b    | User selects Try again                                                                                                                                             | 2.1                                                                     |
| **5**   | **WHEN BIOMETRIC IS INVALID, FIFTH TIME ANDROID**                                                                                                                  |                                                                         |
| **5.1** | **System displays prompt 'Too many failed attempts. Open with PIN'**<ul><li>Actions: Close</li></ul>                                                               |                                                                         |
| 5.1a    | User selects Close                                                                                                                                                 | 5.2                                                                     |
| **5.2** | **System displays prompt 'Biometric not recognized, enter your PIN'**<ul><li>Actions: OK</li></ul>                                                                 |                                                                         |
| 5.2a    | User selects OK                                                                                                                                                    | 1.3                                                                     |
| **6**   | **RECOVER FROM FORGOTTEN PIN**                                                                                                                                     |                                                                         |
| **6.1** | **System displays forgot PIN screen**<ul><li>Forgot PIN?</li><li>Actions: Delete Wallet, Back</li></ul>                                                            |                                                                         |
| 6.1a    | User selects Delete Wallet                                                                                                                                         | Go to: [UC9.4 Wipe all app data](UC9.4_WipeAllAppData.md)               |
| 6.1b    | User selects Back                                                                                                                                                  | Back                                                                    |
<div class="table-notes">1. Resume the state when the app backgrounded/suspended.</div>