After using the Synology CloudSync package to upload 250GB of ENCRYPTED data to Amazon Cloud Drive I quickly realized there was no interface to actually restore these encrypted files from CloudSync itself. After some research I found Cloud Sync Decryption tool provided by Synology.

Some more documentation on the tool can be found by clicking here.

To decrypt the files simply download the files from Amazon or whatever provide you are using, place them in a folder and run the following command:

.\SynologyCloudSyncDecryptionTool.exe -p <PASSWORD HERE> c:\temp\encrypted-files c:\temp\decrypted-files

This will decrypt all your files and place them in an output folder using the password you used to setup the cloud sync backup service.

If you have any questions feel free to contact me!