Microsoft has announced its service worldwide October of 2019.
The new service offers a protected area on OneDrive, which you can only access through one authentication method or a second authentication step, such as your fingerprint, a PIN or a code sent to you via email or SMS .
Your locked files in Personal Vault have an extra level of security, keeping you safe when someone accesses your account or your device. The Personal Vault appears as a special folder in your account.
On Windows 10 devices, Microsoft uses BitLocker to encrypt the files stored in the Personal Vault. The contents of the Personal Vault are encrypted while uploading to Microsoft servers.
Personal Vault is a free unlimited feature for Office 365 subscribers. Users of OneDrive who do not have a subscription will be able to save up to three files in the protected folder.
If you do not have an Office 365 Home or Personal subscription, however, you can put more than 3 files in a ZIP file and upload them to the Personal Vault to bypass the restriction.
OneDrive's Personal Vault is enabled by default. If you do not intend to use it and want to get rid of it, you can turn it off by following these steps:
Note: Disabling Personal Vault will delete all the files you have stored in the Personal Vault folder and cannot be recovered.
To disable the OneDrive Personal Vault,
Open the OneDrive Web site and sign in to the service with your account.
Click the settings gear icon to open the settings
Click on the "Options" link under "Settings"
In the Options, click the Personal Vault tab on the left and click Verify your identity on the right.
Verify your account with one of the available OneDrive methods.
Finally, click Disable.
You can reactivate it at any time by following the same path as mentioned above and with a click on the Enable Personal Vault.