More options for Server Side Encryption in S3

Server side encryption (SSE) for stored files is supported and can be enabled by default for all uploads in the S3 preferences or for individual files in the File → Info (⌘-I) → S3. AWS handles key management and key protection for you. Cyberduck previously supported server-side encryption using SSE-S3 where files are encrypted with a default key managed by S3 using AES-256.

Cyberduck 5.0 and later now supports the use of private keys used for servers-side encryption of files uploaded to S3 managed in AWS Key Management Service (KMS). The dropdown list in the Info panel allows to choose from all private keys managed in AWS Key Management Service (KMS). This requires the kms:ListKeys and kms:ListKeys permission for the AWS credentials used to connect to S3.

AWS SSE-KMS Private Key Selection

You can give it a try in the latest snapshot build.

Support for Backblaze B2


Cyberduck 4.9 adds support for Backblaze B2 Cloud Storage. This includes uploading large files, for files up to 10TB.

Backblaze B2 Cloud Storage works similar to Amazon S3 or Microsoft Azure, allowing you to store unlimited data in the cloud. But does it for 1/4th the cost.

B2 Cloud Storage support in Cyberduck gives you convenient access to low priced redundant and unlimited storage from your desktop.

We are hiring!

Help shaping widely used products in an open source development environment!

We are looking for an experienced Java enthusiast to join our team as an employee or long term freelancer. You help us to drive the integration of cloud storage services into Cyberduck & Mountain Duck and to build up new products from scratch using the latest technologies.

Please refer to our job advertisement for more information.

The cloud on your desktop

We shipped Mountain Duck for Mac & Windows after fixing tons of issues during our private beta to the Mac App Store and for sale from our website! We are excited to get the first positive reviews from users:

(…) The app helps web developers have a less crowded workspace and is sure to make the overall web development a bit easier and faster. –– Softpedia review of Mountain Duck for Windows

(…) All in all, Mountain Duck is a handy utility that could prove to be invaluable for users who commonly manage multiple remote storage servers, as it enables you to mount them as local volumes, and browse their contents or transfer files using Finder. –– Softpedia reviewing Mountain Duck for Mac

Great software. Saves a lot of time. Perhaps you can tell Apple how to implement ftp functionality into Finder as for the last 15 years they seem not to be able to do that. –– MacUpdate comment on Mountain Duck for Mac

(…) Enter this app. It mounts file shares like SFTP, Sharepoint and even my Amazon cloud storage share just like mapping a network drive. Best of all I can use Finder to navigate through the file structures. (…) –– Mac App Store Review

Screenshot Mountain Duck Mac 1440x900

Mind the adware

Adware installers from download sites have become ubiquitous and are now the norm rather than the exception. We therefore urge users to refrain from downloading Cyberduck from download sites such as, or which are or have in the past distributed adware (advertising-supported installers) without our consent. Always download software through the Mac App Store or directly from the developer’s site.

We are also sending out emails to these publishers urging them to stop wrapping our software with an adware  concealing installer and additionally urge Apple to revoke their Developer ID certificate used to distribute the installers (radar://23550056) and/or add the installers to the list of known malware by Gatekeeper.

Update: MacUpdate has removed the adware installer in response to our email claiming the “Cyberduck listing will not be part of any future tests we do with app downloads”.

Update: has removed the adware installer in response to our email confirmed with “ installer has been disabled for this company profile”.

Mountain Duck Private Beta

There have been requests since a long time that we should provide a way to mount remote server storage as a volume in the and File Explorer on Windows, respectively.

We are excited to announce a private beta for Mountain Duck“Cyberduck for mounting volumes in the file explorer”. It comes with a minimal user interface as a status bar application supporting all protocols available in Cyberduck. Mountain Duck mounts the remote storage as a volume to allow any application to access the files for reading and writing.

In contrary to other solutions available for the Mac, Mountain Duck requires no installation of kernel extensions or system libraries and runs sandboxed on OS X 10.8 or later.

Please request an invite to the private beta and let us know how it works for you. Mountain Duck will be available later this year in the Mac App Store and as a Windows Installer.