SecureStore for sensitive data in React Native - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is SecureStore in React Native?

SecureStore is a library that safely stores sensitive data like passwords or tokens on a device using encrypted storage.

beginner

How do you save data using SecureStore?

Use SecureStore.setItemAsync(key, value) to save data securely on the device.

beginner

How do you retrieve data from SecureStore?

Use SecureStore.getItemAsync(key) to get the stored data back securely.

intermediate

Why should you use SecureStore instead of AsyncStorage for sensitive data?

SecureStore encrypts data and protects it with device security, while AsyncStorage stores data unencrypted and is less safe for secrets.

beginner

What happens if you try to get a key that does not exist in SecureStore?

SecureStore returns null if the key is not found, so always check for null before using the data.

Which method saves data securely using SecureStore?

A SecureStore.getItemAsync(key)

B SecureStore.deleteItem(key)

C SecureStore.setItemAsync(key, value)

D SecureStore.loadData(key)

Use setItemAsync to save data securely.

What does SecureStore return if a key is missing?

A undefined

B throws error

C empty string

D null

SecureStore returns null when the key is not found.

Why is SecureStore better than AsyncStorage for passwords?

A It encrypts data

B It is faster

C It uses less memory

D It supports more data types

SecureStore encrypts data, making it safer for sensitive info.

Which SecureStore method retrieves stored data?

A getItemAsync

B setItemAsync

C removeItemAsync

D fetchItem

getItemAsync is used to retrieve data.

What type of data is SecureStore designed to hold?

A Large images

B Sensitive small data like tokens

C App configuration files

D User interface layouts

SecureStore is for small sensitive data like tokens or passwords.

Explain how to securely save and retrieve a user token using SecureStore in React Native.

Think about the methods to save and get data securely.

Why is it important to use SecureStore for sensitive data instead of AsyncStorage?

Consider what happens if someone accesses unencrypted data.

Practice

1. What is the main purpose of using SecureStore in a React Native app?

easy

A. To speed up app animations

B. To store large files like images and videos

C. To manage app navigation between screens

D. To safely save sensitive data like passwords and tokens on the device

Solution

1. Step 1: Understand SecureStore's role

   SecureStore is designed to securely save sensitive data on mobile devices.

2. Step 2: Identify correct use case

   It is perfect for storing passwords, tokens, and private keys, not for files or UI tasks.

3. Final Answer:

   To safely save sensitive data like passwords and tokens on the device -> Option D

4. Quick Check:

   SecureStore purpose = safe sensitive data storage [OK]

Hint: SecureStore is for sensitive data, not files or UI [OK]

Common Mistakes:

• Confusing SecureStore with file storage
• Thinking SecureStore manages UI or navigation
• Using SecureStore for non-sensitive data

2. Which of the following is the correct syntax to save a value using SecureStore in React Native?

easy

A. SecureStore.storeItem('key', 'value');

B. SecureStore.save('key', 'value');

C. await SecureStore.setItemAsync('key', 'value');

D. await SecureStore.putItem('key', 'value');

Solution

1. Step 1: Recall SecureStore method names

   The correct method to save data is setItemAsync, which returns a promise.

2. Step 2: Check syntax correctness

   await SecureStore.setItemAsync('key', 'value'); uses await SecureStore.setItemAsync('key', 'value'); which is correct syntax.

3. Final Answer:

   await SecureStore.setItemAsync('key', 'value'); -> Option C

4. Quick Check:

   Save data = setItemAsync with await [OK]

Hint: Use setItemAsync with await to save data [OK]

Common Mistakes:

• Using incorrect method names like save or putItem
• Forgetting to use await with async methods
• Calling methods without Async suffix

3. What will be the output of this code snippet?

await SecureStore.setItemAsync('token', 'abc123');
const token = await SecureStore.getItemAsync('token');
console.log(token);

medium

A. 'abc123'

B. undefined

C. null

D. Error: Method not found

Solution

1. Step 1: Save a value with setItemAsync

   The code saves the string 'abc123' under the key 'token'.

2. Step 2: Retrieve the saved value with getItemAsync

   Then it fetches the value for 'token', which returns 'abc123'.

3. Final Answer:

   'abc123' -> Option A

4. Quick Check:

   Save then get returns saved string [OK]

Hint: getItemAsync returns saved value if key exists [OK]

Common Mistakes:

• Expecting undefined or null instead of saved value
• Confusing method names or forgetting await
• Assuming error if key exists

4. Identify the error in this code snippet that tries to delete a stored item:

SecureStore.deleteItem('userPassword');

medium

A. Method name should be deleteItemAsync and must be awaited

B. Key 'userPassword' must be a number, not string

C. deleteItem does not exist; use removeItem instead

D. No error; code is correct

Solution

1. Step 1: Check method name for deleting data

   The correct method is deleteItemAsync, not deleteItem.

2. Step 2: Remember async methods require await

   Since it returns a promise, it should be called with await.

3. Final Answer:

   Method name should be deleteItemAsync and must be awaited -> Option A

4. Quick Check:

   Delete method = deleteItemAsync with await [OK]

Hint: Use deleteItemAsync with await to remove data [OK]

Common Mistakes:

• Using wrong method name deleteItem
• Not awaiting async calls
• Thinking key must be a number

5. You want to securely store a user's session token and then immediately retrieve it to verify. Which code snippet correctly does this with error handling?

hard

A. SecureStore.setItem('session', token);
const saved = SecureStore.getItem('session');
console.log(saved);

B. try {
await SecureStore.setItemAsync('session', token);
const saved = await SecureStore.getItemAsync('session');
console.log(saved);
} catch (e) {
console.error(e);
}

C. await SecureStore.saveItem('session', token);
const saved = await SecureStore.getItemAsync('session');
console.log(saved);

D. try {
SecureStore.setItemAsync('session', token);
const saved = SecureStore.getItemAsync('session');
console.log(saved);
} catch (e) {
console.error(e);
}

Solution

1. Step 1: Use correct async methods with await

   Only try { await SecureStore.setItemAsync('session', token); const saved = await SecureStore.getItemAsync('session'); console.log(saved); } catch (e) { console.error(e); } uses setItemAsync and getItemAsync with await properly.

2. Step 2: Include error handling with try-catch

   try { await SecureStore.setItemAsync('session', token); const saved = await SecureStore.getItemAsync('session'); console.log(saved); } catch (e) { console.error(e); } wraps calls in try-catch to handle possible errors safely.

3. Step 3: Identify incorrect method names and missing awaits

   The other options use wrong method names or miss awaits causing errors or wrong behavior.

4. Final Answer:

   Code with await and try-catch -> Option B

5. Quick Check:

   Correct async calls + error handling = try { await SecureStore.setItemAsync('session', token); const saved = await SecureStore.getItemAsync('session'); console.log(saved); } catch (e) { console.error(e); } [OK]

Hint: Always await async SecureStore calls and use try-catch [OK]

Common Mistakes:

• Not awaiting async methods
• Using wrong method names like setItem or saveItem
• Skipping error handling for async calls