Encryption:Remote connections

From Linux 101, The beginner's guide to all things Linux.

[edit] What are remote connections?

Remote connections are made whenever you access files or data on a computer or server different than the one you are currently on or connected to. Some examples of remote connection protocols are ftp, http, rsh, rcp, ssh, scp, sftp, XDMCP, and pop3. These protocols all do various things, and have various security models. Security is not inherent in the various programs themselves, but in the ways they are used.

[edit] Why should I want to encrypt them?

     Most early protocols used on the internet are ASCII based. This means that whatever data is being exchanged be it IMs, email, webpages, passwords, or data, is sent over the internet in a readily readable format, plain text. This is at once a great strength, and a great weakness.

     Easily readable protocols make it easy for humans and machines to parse the packets and create alternate implementations of clients for the various protocols. That is all well and good, until you want to log into a remote machine with your password, buy something online with your credit card, or tell your pen pal you have cancer. Anyone between you and the remote host you are connecting to can have access to your data. The answer to this problem is to use encrypted protocols. Encrypted protocols are methods of communication that have a built in mechanism for obscuring your communications.

     While encrypted protocols are usually built on very difficult to solve math problems, encryption is more like sending your data in an envelope as opposed to writing it on the back of a postcard. The "envelope" can be opened. The goal of encryption is then to make the "envelope" cost more to open than the enclosed data is worth.