DHT in File Sharing: Is It Helpful or Hurtful?

Posted on Feb 3 2015 - 5:36am by admin

You’re into bittorent file sharing, and there are a lot of reasons why this is the ideal method of file sharing. But, at the same time, you’re often faced with a question of security (as well as whether downloading or uploading a file might infringe on copyright). You are, after all, sharing files with strangers on the Internet. How can you be sure that your computer and personal files are not being compromised?

File Sharing

What Is DHT?

DHT stands for “distributed hash table,”and it’s a decentralized distribution system that gives non-members a way to download files from member’s torrents (i.e. a non-member the ability to download from members of a private tracker). This is called “ghost leeching,”because there’s no accountability for the person doing the downloading. They are essentially able to access any file they want, from whomever they want.

Clients using DHT can force downloads from seeders, regardless of whether the tracker is up or down, and it will even share your passkey so that other people can join in the fun – downloading torrents while pretending to be you.

Historically, this was the way early P2P file sharing applications were able to operate effectively. They took advantage of the benefits of DHT, including increased bandwidth and hard disk space from a community of distributed users.

Why Some People Like It

DHT has benefits if you’re looking for faster file downloads. Because it’s open, you can connect to others, and others can connect to you, regardless of whether they’re members of the community or site. On public sites, this can mean downloading files 3, 4, 5, or even 10 times faster than if you shut off DHT.

Finally, using DHT makes your client less dependent on trackers, because it allows you to “talk”directly with other users. If the tracker you’re using crashes, the client can simply go and find other computers. This is how the DHT helps speed up file transfers.

Why Some Don’t

When you use a bittorrent client, on a private site, you’re opening yourself up to being banned and having your computer’s security compromised. That’s because private sites monitor your seed/leech ratio, and they typically don’t allow an unfavorable ratio where leeching is much greater than seeding.

Because people can connect to you anonymously using DHT, it screws up your ratio – bad. Also, because you’re revealing your IP address, and other information about yourself, you become a security risk.

 How To Disable It

If you’re concerned about the (very real and serious) security issue surrounding DHT, disable it. To disable it in a client like µTorrent, open the program, then go to “options,”select “preferences,”and then “Torrent Options.”

Uncheck the “Enable DHT”option. Hit “apply”and then hit “OK.”You should now see “DHT: disabled>’on the bottom of the main window. Save, and then restart the client.

On a bittorrent client, like Vuze, go to “tools,”“options,”“connection”and then under “peer sources,”select the default permitted sources for peer connections.”Now, make sure you only check “from a tracker.”Back out of there and go to “plugins.”Select “distributed DB,”and uncheck “enable the distributed database.”

Finally, go to “sharing.”Check “private torrent.”Now select “allow decentralized tracker when tracker is unavailable.”

Save your settings and restart the client.

On Vuze, go to “tools,”“options,”“connection,”“peer sources,”and then uncheck “decentralized tracking.”This will disable DHT. Now, save your settings, and restart Vuze. That’s it. You’re secure. Just make sure that you respect IP and don’t infringe on copyright.

Mary Martin is a law student with a flair for technology. An avid blogger, you can read her helpful articles on many technology and legal blogs.