The security built around Active Directory was designed to protect valuable network assets. Development of Windows Server 2008 R2 security has also been affected by the Trustworthy Computing initiative by Microsoft, which changed the primary focus of Microsoft products to security. In a nutshell, Microsoft is more focused than ever before on the security of its products, and all new features must pass a security litmus test before they can be released. This initiative has affected the development of Windows Server 2008 R2 and is evident in the security features.
Understanding Kerberos Authentication
Kerberos was originally designed at MIT as a secure method of authenticating users without actually sending a user password across the network, encrypted or not. Being able to send a password this way greatly reduces the threat of password theft because malicious users are no longer able to seize a copy of the password as it crosses the network and run brute-force attacks on the information to decrypt it.
The actual functionality of Kerberos is complicated, but essentially what happens is the computer sends an information packet to the client that requires authentication. This packet contains a “riddle” of sorts that can be answered only by the user’s proper credentials. The user applies the “answer” to the riddle and sends it back to the server. If the proper password was applied to the answer, the user is authenticated. Although used in Windows Server 2008 R2, this form of authentication is not proprietary to Microsoft, and is available as an Internet standard. For a greater understanding of Kerberos security.
Taking Additional Security Precautions
AD DS implementations are, in essence, as secure as the Windows Server 2008 R2 environment in which they run. The security of the AD DS structure can be increased through the utilization of additional security precautions, such as secured server-to-server communications using IPSec or the use of smart cards or other encryption techniques. In addition, the user environment can be secured through the use of group policies that can set parameter changes such as user password restrictions, domain security, and logon access privileges.
Source of Information : Sams - Windows Server 2008 R2 Unleashed