ssh and sftp provide a "secure" alternative by using public key encryption during the login sequence, and additional encryption (DES, I believe) for all subsequent data exchanges.
For assignment 6, we'd like everyone to use ssh and sftp in place of telnet and ftp when working with our remote accounts on fuseki.cs.washington.edu and madalton.cs.auc.dk.
To use ssh with the above two accounts, you'll need the following commands:
ssh -l comp249 fuseki.cs.washington.edu
ssh -l jeffay madalton.cs.auc.dk
After giving one of the two commands, you'll type the account password (see me for them)
which will be encrypted and sent over the wire. After authentication, you'll have a command prompt
on the remote machine using a secure connection.
Note that I've already placed the public key for each of these machines in your home directory under /home/username/.ssh2/public/hostkeys. (You don't need to do anything with this directory, I'm merely pointing it out FYI.)
To use sftp with the above accounts, use these commands:
sftp fuseki.cs.washington.edu comp249
sftp madalton.cs.auc.dk jeffay
Similarly, after giving one of the two commands, you'll type the account password
which will be encrypted and sent over the wire. After authentication, you'll have an ftp command prompt
on the remote machine using a secure connection.
Note that sftp always uses binary mode. That is, there is no ascii mode, which shouldn't make any difference for what you'll need to do.
See the man pages on ssh and sftp for further information, and http://www.ssh.fi for the actual download site.