Hello Ketan,
Microsoft's NTLM SSP does not provide you with the full SNC protection capabilities. To enable data integrity and privacy protection with NTLM, you need to use an additional security product, for example SAP Single Sign-On. We recommend that you use Kerberos for SAP GUI Authenticationfor system environments consisting of Microsoft Windows 2000 and higher.
Please, also consider the fact that Microsoft also recommend to implement Kerberos instead of NTLM:
"The Microsoft Kerberossecurity package adds greater security than NTLM to systems on a network. " See the statement here: Microsoft NTLM (Windows)
Regards,
Donka Dimitrova