Ed2k is a file-sharing network introduced by the client edonkey2000 (in short ed2k) developed by MetaMachine.
Nowadays the most common software is Emule which started as open source by reverse engineering the original edonkey2000 client and is now far more developed than any other client software that is able to speak the ed2k-Protocol and therefore able to connect to the ed2k network.
While ed2k uses a mixture of client-server and peer to peer communication just like Kazaa or Napster where "Servers" communicate the connections between peers and relay search queries, there has been development on another network called kademlia or overnet which communicates without those "Servers" and making the whole network less vulnerable. Though the advantage of the client-server aspect is the speed at which peers find files and other peers the downside is that the network will start falling apart if these servers are attacked or taken down.
On Kademlia on the other hand, each node in the network is equally important and the network will not be damaged if a single node is removed which my happen when it's beeing attacked or someone simply switches off his computer.
An ed2k link found on several websites usually look like:
It consists of several parts:
- ed2k:// defines the protocol and tells the browser to submit this link to the ed2k client
- |file| tells the ed2k client what type of link this is. The most common is |file|
- |file.txt| defines the filename
- |123| is the size of the file in bytes
- |1234567890abcdef1234567890abcdef| is the MD4 hash checksum of the file to verify it has been transfered correctly. Every file on the ed2k network is uniquely identified by this hash and not by the filename.
- |h=1234567890ABCDEF| is the (optional) AICH hash checksum which is used by Emule to provide additional corruption protection.
To create those links either rightclick on a file in your ed2k client or use the standalone eMule-LinkCreator which can be separately downloaded from the eMule Project Sourceforge homepage
The LinkCreator offers several options to create the ed2k links, although there are only a few settings needed to start creating an ed2k link:
- Select the file you want to create the link for. You can also use wildcards as * to make it create links for multiple files at once
- Leave all other options as they are as they are not important to the normal link usually used, except
- Create Links with AICH hash is usually a good option to allow other clients some improved corruption handling
- Do NOT Create Links with Hashset, as this dramatically increases the size of the link and usually makes it unusuable as clickable link on most websites
- Click on Generate to finally start the computation of the hashes and the LinkCreator will display the links in the box right above the button