jack.minardi.org : SyncNet: A Decentralized Web Browser

Imagine if we lived in a world where more demand meant less load for a webserver. Imagine if we lived in a world where no organization could take down a website, and everyone could publish a site with no hassle or upfront cost. SyncNet is a first step into that world.

SyncNet is an experimental new browser built on top of BitTorrent Sync and (soon) Colored Coins. Every time you access a site, you store all of its contents on your machine. The next user to request the site can get the contents from both your machine and the original server. As more people access a page, it becomes available from more machines, reducing the load on the original server.


SyncNet uses BitTorrent Sync to handle distributing the content of a site and Colored Coins to handle domain resolution. (Colored Coins not implemented yet.)

BitTorrent Sync

BitTorrent Sync uses the BitTorrent protocol to keep directories in sync across the internet, much like DropBox. Say you have two folders that you want to keep in sync, one at home and one at work. On one of the computers you add the directory to BTSync, and it will give you a "secret". (A secret is a string of 33 characters - 160 bits encoded in base32) Now on the other computer you add a new folder using the same secret and they will stay in sync as long as they are both connected to the internet. BTSync works behind the scenes breaking up your files into little chunks and pushes the changes between both computers, and it does this all without requiring a central server like DropBox does.

Along with the secrets mentions above, BTSync also lets you generate "read only secrets". If you share your read only secret with someone they will be able to download your files, but they will not be able to make changes that will be synced back to your computer. Every secret has a corresponding read only secret.

Colored Coins

Colored Coins are a new idea that enable "smart property" and are implemented on top of the BitCoin protocol. Colored Coins essentially allow you to color a certain coin and mark that it represents ownership of something else. In SyncNet a colored coin will represent ownership of a domain name. Anyone with access to the Bitcoin blockchain (which is public data) will be able to see who owns a domain name and what secret it resolves to.

The current implementation of SyncNet does not use Colored Coins, but that should be coming soon.

Tying it together

You can probably see where this is going. All SyncNet does is use BTSync to fetch a directory of HTML files and then renders them for the user. If those HTML files include a hyperlink to a URL starting with sync://<secret> then that secret will be added and the contents of the new directory will be displayed.

Because all the heavy lifting is done by BTSync and a QWebView, SyncNet itself is quite small. You can browse all the source code on github.

User Interface

Here is a screen shot of the current SyncNet user interface:

I am serving the website you are currently reading under the read only secret B4KWMK3VBJSH35YZMS7ZEMSQ6XNVBHALY

Entering that secret in the URL bar of SyncNet will cause it to fetch my whole site and display the index page. Now any time I update my website the changes will be synced to anyone who has downloaded it. SyncNet monitors the directory and refreshes the page if any changes are detected. This is useful because if anyone with a read/write secret makes changes to the pages, all connected clients will quickly reflect that change.

To add your own content to SyncNet you just need to add a directory of HTML files to BitTorrent Sync. This can be accomplished in SyncNet easily by clicking the plus icon in the top right. That will open up the following dialog:

Using this dialog you can create a new SyncNet site. You must generate your secret from a seed, which is just a string of characters. Anyone who knows this seed will be able to recover your secret. And remember, anyone with your secret is able to modify the contents of your site. So keep this seed secret! (And keep your secret secret!)

Once you are satisfied with your seed, click "Ok" and your new SyncNet site will be added. A directory should pop up, and if you drop HTML files into this folder, they will be served to anyone who requests your page.


SyncNet only works with static content. This means no social networks or other dynamic content. However many sites today do not need to be dynamic and would benefit from converting to only static resources. Most blogs or news sites could be served with SyncNet with little to no modifications.

Another caveat is long load times. This is because SyncNet needs to pull down all files for a requested site, not only those needed to render the current page. However BTSync has selective sync capabilities so this could be improved in the future. At the very least ensuring that the index page is synced first would go a long way in speeding things up.

Future Work

As mentioned above, a major missing piece is domain resolution. This will be implemented with Colored Coins (or something similar such as namecoins.)

It would also be nice to be able to create a sync site from any WWW site that currently exists. Browse to a page you like in SyncNet, click on a single button and convert the site to a new SyncNet site.

Another future goal is to implement SyncNet as a chrome or firefox plugin, where a whole separate browser is not needed. This may be possible in the future.


I was pretty happy with how little work it ended up being to tie these technologies together into SyncNet. While SyncNet may not be the implementation that exists into the future, I believe it is a step down the path that the internet seems to be going. Decentralizing more and more aspects of the core technologies of the internet will make it more robust in the face of targeted attacks and censorships attempts.

If you like these ideas feel free to submit a pull request on github or reach out to me on twitter.