Explain the various computer security classification recognised by trusted computer system Evaluation criteria (TCSEC)

Trusted computer system evaluation criteria is a united states government Department of Defense standard that sets basic requirement for assessing the effectiveness of computer security controls built into a computer system. The TCSEC was used to evalute, classify and select computer system being considered for the processing, storage and retrieval or classified information.

Divisions and classes:

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 higher division.