Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Wikipedia.


(National Computer Security Center) The arm of the U.S. National Security Agency that defines criteria for trusted computer products, which are embodied in the Orange Book and Red Book. Published in the 1980s and 1990s and known as the Rainbow Series because of their colored covers for each topic, they have been largely superseded by the Common Criteria. See also NCSA.

Orange Book
The Orange Book contains the "Trusted Computer Systems Evaluation Criteria" (TCSEC), DOD Standard 5200.28.

Red Book (for networks)
The Red Book contains the "Trusted Network Interpretation of the Trusted Computer System Evaluation Criteria" (NCSC-TG-005) and "Trusted Network Interpretation Environments Guideline: Guidance for Applying the Trusted Network Interpretation" (NCSC-TG-011).

Level D
Systems are rated on a scale starting from D, which is not secure, to A, which is the most secure.

Level D is a non-secure system.

Level C
Level C provides discretionary access control (DAC). The owner of the data can determine who has access to it.

C1: Requires user login, but allows group ID.

C2: Requires individual user login with
password and an audit mechanism.

Levels B and A
Levels B and A provide mandatory access control (MAC). Access is based on standard DOD clearances. Each data structure contains a sensitivity level, such as top secret, secret and unclassified, and is available only to users with that level of clearance.

B1: DOD clearance levels.

B2: Guarantees path between user and the
security system. Provides assurances
that system can be tested and clearances
cannot be downgraded.

B3: System is characterized by a mathematical
model that must be viable.

A1: System is characterized by a mathematical
model that can be proven. Highest
security. Used in military computers.

European Ratings

The European Information Technology Security Evaluation Criteria (ITSEC) is similar to TCSEC, but rates functionality (F) and effectiveness (E) separately.

        D       E0
        C1      F-C1, E1
        C2      F-C2, E2
        B1      F-B1, E3
        B2      F-B2, E4
        B3      F-B3, E5
        A1      F-B3, E6
References in periodicals archive ?
Similar benefits for the NCSC also have occurred in other states (e.
Customer satisfaction surveys confirm rising levels of customer satisfaction with NCSC services.
The NCSC is working closely together with the affected organisations, companies and persons from the cyber security community, the Public Prosecution Service and the Police in order to remove the threat.
Mrs Ryding met inspectors on Monday in a bid to resolve the outstanding problems and an NCSC inspector is now understood to be working closely with the clinic to resolve the issue.
If you think of all of the thousands of truck drivers and cargo handlers, it's going to be a major undertaking," concedes NCSC Executive Director Joe M.
The studies are available from the NCSC at (800) 228-NCSC.
The NCSC has deployed additional SPSS predictive analytics software for its research and court consulting branches.
Earlier, another IPS officer Puran Kumar had also written a similar letter to the NCSC against Ambala commissioner Ajay Singhal.
NCSC is an ambulatory surgery center adjacent to Tri-City Medical Center's campus on Waring Road in Oceanside.
The NCSC contacted Coventry Homes and listed them for a tribunal and told them they had a flimsy case.
A spokesperson for the NCSC said: 'We will continue to protect people from poor care.
Set up by the Department of Health in April to eliminate regional differences in standards of care, the NCSC has taken over responsibility from individual local authorities for the regulation and inspection of foster care services throughout the UK.