Those with a background in unix administration are familiar with ssh which is a secure shell. It generally includes a telnet that can't be sniffed, a secure ftp, a secure forwarding of services and a secure file copy utility. The initial version had vulnerabilities in its encryption that could be exploited. SSH version 2 corrects those defects. It is the remote administration utility of choice for unix admins. Versions are available to securely administer Windows NT and Windows 2000 servers.

• Ssh Secure Shell Resources (my more general tip)

• Chaffee's port of ssh and SCP for Windows 95 and NT (command line only version)
  free client for Windows
• Cygwin OpenSSH
• FiSSH Secure Shell Client for Windows 95 and NT 4.0
  free client for Windows
• F-Secure SSH Client / Server
  commercial product
• Labtam's SSH Pro : SSH Client
  commercial product
• man pages / tutorials / howtos
  • All About SSH
    
  • OpenBSD SCP Manpage
    
  • OpenBSD SSH Manpage
    
  • How to use SSH
    
  • SSH: From Secure Administration to Virtual Private Networking
    
• OpenSSH v2.9p2-3 on Windows
  free, open source
• Piotr Kucharski _free_ version of SSH for Windows
• PuTTY
  free SSH client for Windows
• Secure iXplorer
  what you need for secure FTP, VNC and Terminal sessions
• ShellGuard
  commercial product SSH2, SSH1, scp and Telnet are all supported in a single client
• TTSSH: An SSH Extension to Teraterm
  free SSH client for Windows
• WinSSHD
  commercial, a Windows NT4/2000 SSH Secure Shell 2 server
• WinSCP
  WinSCP is a freeware SCP (Secure CoPy) client for Windows 95/98/NT/2000/XP/ME using SSH (Secure SHell). Its main function is safe copying of files between a local and a remote computer. WinSCP can do all basic operations with files, such as copying and moving (to and from a remote computer). It also allows you to rename files and folders, create new folders, and change properties of files and folders.
  

• scanssh protocol scanner scans a list of addresses and networks for running SSH protocol servers
• Remote vulnerability in SSH daemon crc32
• Make SSH do more
• Secure forwarding of services with SSH
• A Quickstart Guide to the Secure Shell (SSH)
• SSH and beyond...
  security issues when using SSH over NFS
• SSH documentation on www.heimhardt.de

If you are wondering about the telnet build into Windows 2000 and XP, it supports native NTLM authentication which encrypts passwords. This is only useful if its two W2K boxes communicating. Telnet to anything else and its all plain text passwords and commands. And guess what, even the W2K-to-W2K telnet only encrypts the passwords and nothing else.

If you need security with your unix.