How it works

Intro

Click2Copy overcomes common problems in modern communication protocols: It connects two computers independent of their geographical locations and their network restrictions. It doesn't matter whether you or your recipients are behind a firewall or a proxy server: Click2Copy is smart enough to connect your computers, establish a secured channel between them and transfer any amount of data over this channel on the speed of your actual connection.
You might think, there already exist software packages accomplishing this task, but: In order to use this wonderful piece of technology you don't need to install any complicated software at all, Click2Copy is working directly in your browser! And guess what? It's absolutely free of charge!

Technology

Click2Copy is written in Java and runs in the browser by means of the Java-Plugin integrated in it.
In order to support legacy Java installations, the client part of Click2Copy has been developed to be compatible with a relatively old version of java: 1.4. Of course, it works perfectly fine with newer versions as well.
Click2Copy is a peer-to-peer service, hiding away a complex communication schema used to establish a data transmission channel between two computers.
Under the hood Click2Copy works very extensively in order to select the most efficient communication schema: It checks the efficiency of direct and relayed communication with different protocols available at the client side (such as UDP or HTTP). The best protocol is used to transmit the data.
Most of the protocols used in the application are developed exclusively for Click2Copy, including new UDP based transfer protocols adapted for large-file transfer.

Common communication algorithm

Three major parties take part in a normal Click2Copy file transmission session: Server, sender and receiver.
The sender initiates the communication: The user selects a file to send and optionally selects the name and password for the transmission. If the user doesn't provide the name for the transmission the name is auto-generated. The auto-generated transmission names can't be secured by a password.
After pressing the send button the server registers the name of the communication and publishes it on the site under a URL having the format http://click2copy.com/receive/<name> where <name> denotes the user-defined or auto-generated name for the transmission.
There is very special type of transmission names: Email-like names (like, receipient.name@recipient.domain.com). Instead of an arbitrary name the sender can choose to select the other user’s email as a name for the transmission. In that case the intended recipient will get an email notification containing the URL to the file transmission.
The intended recipient opens this link in order to gain access to the file.
When the receiver opens this link the Click2Copy application is started in the browser. As a result, the secured communication channel is established between the sender and receiver. This process is strongly supported by the server, which provides information about the computer’s locations and communication protocol peculiarities on both of the involved sides. After the communication channel is established the data stream is sent directly from the sender to the receiver without direct intervention from the server.