Encrypting File System (EFS) Support
Microsoft added support for the encrypting file system (EFS) in Windows 2000. The EFS feature allows users to transparently encrypt files or folders to protect their confidential data. Let's examine a couple of major areas of EFS where the security has been enhanced:
The first one has to do with how encrypted files behave when they are saved on a network server. In Windows 2000, when a user opens a file that's located on the server, it's decrypted so the user can read it. When the user saves the file, it is re-encrypted. However, while the data travels between the client's computer and the server, it's not encrypted. In other words, someone running a NetMon or a sniffer can potentially capture and read the data. This behavior has been changed in Windows .NET; the data traveling across the wire is now encrypted. (Makes you wonder, thoughwhy didn't they implement this feature before?)
The second cool feature has to do with sharing encrypted files. Now you can finally share your encrypted files with other members of your group. The advantage here is that you can share confidential files with other users, either over a public network or over a LAN.