For Mac users who put their external hard drives and USB flash drives, the time may come in which wish to remove password protection and decrypt the external device. Deciphering an external disk allows all data stored therein are accessible without password authentication.
It is important to remember that this process of decrypting external disks is totally different from the FileVault encryption used on a Mac to the internal disk. FileVault does not encrypt external hard drives, thus decoding an external drive in this way not decrypts an internal disk FileVault.
How to disable encryption and decryption in Mac external drives
This is the primary method to disable the encryption and decipher any external volume that has been encrypted using encryption tools built into modern versions of Mac OS X and MacOS. This will remove password protection from the destination drive.
- Connect the drive or volume you want to decrypt on the Mac
Select the external disk (either from your hard drive, from Finder, or from the device menu in the Finder sidebar) and click on the drive icon and select "Decrypt ..." in the list.
Enter the password that was used to encrypt and lock the drive to unlock the content and start the decryption process.
Deciphering the external drive can take a while, depending on how big it is. You can check the status by returning to right-click context menu.
When finished, use the new deciphered as usual or expel it from the Mac disk.
Once the unit has been deciphered no longer have any protection on it, which means you can access or read without the password entry requirements.