What is arXshare?

arXshare is a secure and lightweight file sync solution. It allows anyone to easily host a private file cloud, and securely collaborate with family members, friends, colleges, or customers over the internet. It is free for personal use of up the three users. Think of it as your personal, secure fortress, where files are locked-in and only you decide who has access.


Is it complicated to use?

No, it easy to install and to use. Please check out our screenshot section to see some impressions of the user interface. Furthermore, we have a video online that will show how easy it is to install arXshare.


What are the design principles of arXshare?

arXshare was designed with three design principles in mind:

  1. security: using high cryptographic standards and zero-knowledge policy, to ensure the privacy of your files.
  2. control: give the control of files back into your hands. Only you decide where your data is stored and who has access to it.
  3. simplicity: arXshare is easy to install and use, so that everyone can use this technology.


How does arXshare compare to other file share and file sync solutions?

If you like Dropbox or Google Drive, you will love arXshare. It is as easy to use, but instead of storing your files somewhere on the planet, you decide where your files are stored. Also, you have 100% control of your data and who has access to it, therefore retain control of your intellectual property. Even when arXshare is hosted on an insecure network, it’s secure architecture prevents cyber thieves, competitors, or government agencies to eavesdrop.


Why is arXshare secure?

arXshare was specifically designed with the highest demands for security and privacy. It uses state-of-the-art cryptographic standards to protect your files. Compared to its competitors, arXshare does end-to-end encryption. This means that your computer or mobile device encrypts and scrambles the files before sending it to the server. This zero-knowledge design ensures that no one, not even the arXshare server, has any knowledge of the content of your files. Only with your password, or when you share files with others, the files can be decrypted again.


Why shouldn’t I use TrueCrypt on Dropbox, Google Drive, etc.?

The problem of using secure volumes like TrueCrypt on Dropbox or Google Drive is that this will often cause conflicts during synchronization. The reason is that even when two person change different files, the conflict cannot be resolved automatically, as the same True Crypt container was changed simultaneously. This will not happen when using arXshare because it handles files individually.


What are the minimum requirements for arXshare?

The arXshare server was specifically designed to be lightweight and reduce its system requirements to a minimum. All you need is a Web server with PHP 5.3 or higher. No database or admin rights are required, any simple Web space for less than three bucks a month will do.
However, keep in mind that the speed of your provider directly affects the performance of arXshare when uploading or downloading files. Therefore, we recommend that you check the upload and download performance of a provider before you deciding to host arXshare.
The arXshare client is a Windows program that, similar to the Dropbox or Google Drive client, synchronizes your files to the server. Mobile clients for Android and iPhone are coming soon.


How do I install arXshare?

arXshare was specifically designed to be easy to install. All you do is uploading an install-script to your Web space and open it in your browser. The script will download the arXshare server and a wizard will guide you through the configuration of your new, personal file cloud.


How can I invite others to my private arXshare file share?

After installing the arXshare server, the admin console lets you invite others to your private file cloud. Simply add users, and they will receive an e-mail invitation. During log on, they have to change their password and RSA keys are generated. When the RSA keys are available for a user, you can securely share folders with them.


What is the technology behind arXshare?

When a user uploads files to the server, the arXshare client splits each file into one megabyte chunks. Each chunk is zipped and encrypted, using AES-256 with an unique key and IV. Then, the chunks are transferred to the server. Only with the user’s password, this data can be decrypted and reassembled to the original file’s content. Therefore, neither the server (zero-knowledge) nor an eavesdropper has any indication how these chunks relate and what the content of the file is.


What technology is arXshare using?

arXshare is using end-to-end encryption and state-of-the-art cryptographic standards to secure your files:

  • The arXshare client cuts files into chunks and encrypts them using AES-256.
  • The server has zero-knowledge and therefore no ability to decrypt files. The encryption is end-to-end between clients.
  • The user’s main AES-256 key is derived by using the Password-Based Cryptography Specification (PKCS #5) according to RFC-2898.
  • Each directory stored in arXshare has it’s own AES credentials, which are encrypted using the user’s main AES key
  • When a user connects to arXshare the first time, the arXshare client will generate a unique pair of RSA-keys with 2048 bit strength.
  • For invitations, the AES key and IV for the specific folder is encrypted with the public key of the invitee, hence, only this user is able to decrypt the invitation, and see shared folder.