Decrypt the specified SD card file which was previously encrypted with Tasker's Encrypt File action.
The path starts in the root directory of the SD card e.g. secret.txt, secret/recording.mp3.
Key Name is the name of the encryption key to use.
The key is not deleted unless Clear Key is set, since you will usually want to use the same key to encrypt the file again at some point.
There must be space left on the SD card at least equal to the size of the file before starting decryption.
See Encryption in the Userguide for details.