C2 is labeled Controlled Access Protection.
The TCSEC defines four divisions: D, C, B and A where division A has the highest security.
Each division represents a significant difference in the trust an individual or organization can place on the evaluated system. Additionally divisions C, B and A are broken into a series of hierarchical subdivisions called classes: C1, C2, B1, B2, B3 and A1.
Each division and class expands or modifies as indicated the requirements of the immediately prior division or class. D — Minimal protection
Reserved for those systems that have been evaluated but that fail to meet the requirements for a higher division
C — Discretionary protection
C1 — Discretionary Security Protection Identification and authentication Separation of users and data Discretionary Access Control (DAC) capable of enforcing access limitations on an individual basis Required System Documentation and user manuals
C2 — Controlled Access Protection More finely grained DAC Individual accountability through login procedures Audit trails Object reuse Resource isolation
B — Mandatory protection
B1 — Labeled Security Protection Informal statement of the security policy model Data sensitivity labels Mandatory Access Control (MAC) over selected subjects and objects Label exportation capabilities All discovered flaws must be removed or otherwise mitigated Design specifications and verification
B2 — Structured Protection Security policy model clearly defined and formally documented DAC and MAC enforcement extended to all subjects and objects Covert storage channels are analyzed for occurrence and bandwidth Carefully structured into protection-critical and non-protection-critical elements Design and implementation enable more comprehensive testing and review Authentication mechanisms are strengthened Trusted facility management is provided with administrator and operator segregation Strict configuration management controls are imposed
B3 — Security Domains Satisfies reference monitor requirements Structured to exclude code not essential to security policy enforcement Significant system engineering directed toward minimizing complexity Security administrator role defined Audit security-relevant events Automated imminent intrusion detection, notification, and response Trusted system recovery procedures Covert timing channels are analyzed for occurrence and bandwidth An example of such a system is the XTS-300, a precursor to the XTS-400
A — Verified protection
A1 — Verified Design Functionally identical to B3 Formal design and verification techniques including a formal top-level specification Formal management and distribution procedures An example of such a system is Honeywell’s Secure Communications Processor SCOMP, a precursor to the XTS-400
Beyond A1 System Architecture demonstrates that the requirements of self-protection and completeness for reference monitors have been implemented in the Trusted Computing Base (TCB). Security Testing automatically generates test-case from the formal top-level specification or formal lower-level specifications. Formal Specification and Verification is where the TCB is verified down to the source code level, using formal verification methods where feasible. Trusted Design Environment is where the TCB is designed in a trusted facility with only trusted (cleared) personnel.
The following are incorrect answers:
C1 is Discretionary security C3 does not exists, it is only a detractor B1 is called Labeled Security Protection.
Reference(s) used for this question:
HARE, Chris, Security management Practices CISSP Open Study Guide, version 1.0, april 1999. and AIOv4 Security Architecture and Design (pages 357 -361) AIOv5 Security Architecture and Design (pages 358 -362)