> For the complete documentation index, see [llms.txt](https://cramiumlabs.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cramiumlabs.gitbook.io/docs/sdk-mpc-ios/usage-guide-for-an-mpc-wallet-app/backup-restore.md).

# Backup/Restore

To ensure wallets can be securely backed up and restored, users need to create a **Secure Encryption Key (SEK)**. Each user has only one SEK, which is used to encrypt wallet data for backup and decryption during restore.

#### 1. Store Backup Data

* The SEK is used to encrypt wallet data for backup purposes, call `storeBackupData()`
* `data`: The SEK in `ByteArray` format to encrypt. **Example**:

```swift
 client.storeBackupData(data: Data)
```

#### 2. Get Backup Data

* To restore wallets, call `getBackupData()` to retrieve the SEK for decryption. **Example**:

```swift
 let data = client.getBackupData()
```