Cisco offers three levels of certification depending upon the depth of knowledge required in each stream namely Entry Level, Associate, Professional and Expert.
CCNP Security is an Professional level certification.
CCNP Security is for Cisco Network Security Engineer responsible for Security in Routers, Switches, Networking devices and appliances, as well as choosing, deploying, supporting and troubleshooting Firewalls, VPNS, and IDS/IPS solutions for their networking environments.
To obtain CCNP Security certification, the exams required are:
300-208 SISAS : Implementing Cisco Secure Access Solutions (SISAS)
300-206 SENSS : Implementing Cisco Edge Network Security Solutions (SENSS)
300-209 SIMOS : Implementing Cisco Secure Mobility Solutions (SIMOS)