Bitlocker vs File Encryption for Cloud Files

**Hi!**  
These are two different protection systems, and their scopes are also distinct:

### BitLocker
- BitLocker encrypts the physical disk or local volume.  
- Its protection applies while the data is stored on that disk.  
- If someone steals the disk or boots the machine without the key, they cannot read the files.  

☁️ Files synchronized with OneDrive
- When a file is synchronized with OneDrive, it is copied to cloud storage.  
- That copy no longer depends on local disk encryption: it is stored on Microsoft servers under their own security mechanisms.  
- When accessing from another device, OneDrive delivers the file decrypted (because BitLocker encryption only applies to the original disk, not to the cloud copy).  
- Protection in this case depends on:  
  - Microsoft/Office 365 account credentials.  
  - Multi-factor authentication (MFA) if enabled.  
  - Encryption in transit and at rest applied automatically by OneDrive.  

### Properties > General > Advanced > Encrypt Contents (EFS)
- EFS encrypts individual files and folders on an NTFS volume.  
- The encryption is based on a certificate and private key associated with the Windows user who performed the encryption.  
- Only that user (or anyone with the exported/imported certificate) can open the file on that machine.  

### ☁️ What happens when synchronizing with the cloud (e.g., OneDrive, Google Drive, Nextcloud)
- When a file encrypted with EFS is synchronized or copied to the cloud, it is uploaded already encrypted.  
- On another device, when downloaded, the file remains encrypted.  
- To open it, that other device must have the same EFS certificate imported into the user profile.  
- Without the associated private key, the file will appear unreadable or inaccessible.  

Hope this was helpful.

JADM