Hi,
their are several ways to secure your SQL Server
1). Strengthen Password Mechanism
2). Using NTFS File System
3). Change the Port of SQL Server other than default
4). Use named instance
5). Set firewall
6). Using Windows Authentication
7). Using EFS
i would suggest to refer below links for more :
http://vyaskn.tripod.com/sql_server_security_best_practices.htm
www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sqlc2.mspx -- C2 Audit
http://www.sql-server-performance.com/ck_database_encryption.asp
http://www.sqlservercentral.com/columnists/bkelley/implementing_efs.asp
http://www.microsoft.com/sql/prodinfo/previousversions/securingsqlserver.mspx
Regards
