TCSEC is one of the foremost trusted computing base, started in the 1960s and is today the model for various other off-shoots such as the ITSEC(Information Technology Security Evaluation Criteria), the CC (Common Criteria aka ISO15408), BS7799, ISO/IEC 17799. The TCSEC was primarily defined for standalone computer systems of the 1960s and is popular refered to as the Orange Book. The Trusted Network Interpretation(TNI or Red Book ) is the modern Network version ). The TCSEC was developed as a framework for determining achievable trust levels in computing systems developed by various vendors. The TCSEC's goal was a unified evaluation mechanism for vendors to reference their products by and for consumers to rate those products to.
The TCSEC's primary objective was confidentiality and seven Assurance levels were defined:
C2 : Support C1 protections and Object Re-Use Protection Enables Protected Audit Track
B1 : Supports C2 protections and Allows Mandatory Access Control Provides Label Protection
B2 : Supports B1 protections and Provide Trusted path Enables Covert Channel Annalysis
B3 : Supports B2 protections and Provides Trusted Recovery
A1 : This is the ultimate stage and it not only supports B3 protections but also requires a formal Design Verification.
Covert Channel Annalysis is an highly involved process that requires the identification of possible covert channels that may be available in memory and analysis of their impact as well as justification for their allowance within the completed system. This requirement alone ensures that most systems, even today, hardly go beyond B1 on the TCSEC scale.
In my words: A covert channel is any part of a system that could be used to transmit or glen information from or about a system in a non-tradditional, non-authorized manner.
A Standard Definition: A covert channel is a mechanism for exchanging information about a system in a manner that circumvents the security policy of the system.
There are different types of covert channel but the more popular classifications are Covert Timing Channels (CTC) and Covert Storage Channels (CSC). In simple terms, timing channels rely on time synchronization, delays and related timing structures of a system for operation. A storage channel on the other hand rely on what is stored or can be stored in some memory for its operations.
Some time in the future, I will review the topic and provide examples as well as clear descriptions.
--- Sorry, I get to post something when I have a few minutes and that does not always allow for a coplete and comprehensive treamtment at a go. My expectation is that as I revisite the site and discovered uncompleted ideas or thoughts, I will update them. Also, when I have larger chunk of time on my hand I will develop the more complex ideas further and provide as much insight as possible into the workings of some of the technologies I allude to here.
3 comments:
TCSEC is one of the foremost trusted computing base, started in the 1960s and is today the model for various other off-shoots such as the ITSEC(Information Technology Security Evaluation Criteria), the CC (Common Criteria aka ISO15408), BS7799, ISO/IEC 17799. The TCSEC was primarily defined for standalone computer systems of the 1960s and is popular refered to as the Orange Book. The Trusted Network Interpretation(TNI or Red Book ) is the modern Network version ).
The TCSEC was developed as a framework for determining achievable trust levels in computing systems developed by various vendors. The TCSEC's goal was a unified evaluation mechanism for vendors to reference their products by and for consumers to rate those products to.
The TCSEC's primary objective was confidentiality and seven Assurance levels were defined:
D : Provides minimal or no protection
C1 : Allows Discretionary Access Control, Provides Object Identification and Authentication
C2 : Support C1 protections and
Object Re-Use Protection
Enables Protected Audit Track
B1 : Supports C2 protections and
Allows Mandatory Access Control
Provides Label Protection
B2 : Supports B1 protections and
Provide Trusted path
Enables Covert Channel Annalysis
B3 : Supports B2 protections and
Provides Trusted Recovery
A1 : This is the ultimate stage and it not only supports B3 protections but also requires a formal Design Verification.
Covert Channel Annalysis is an highly involved process that requires the identification of possible covert channels that may be available in memory and analysis of their impact as well as justification for their allowance within the completed system. This requirement alone ensures that most systems, even today, hardly go beyond B1 on the TCSEC scale.
Errata:
The TCSEC was actually published on December 26, 1985 as
DoD 5200.28-STD. Sorry about the 20 years lead time :)
What is a covert Channel?
In my words: A covert channel is any part of a system that could be used to transmit or glen information from or about a system in a non-tradditional, non-authorized manner.
A Standard Definition: A covert channel is a mechanism for exchanging information about a system in a manner that circumvents the security policy of the system.
There are different types of covert channel but the more popular classifications are Covert Timing Channels (CTC) and Covert Storage Channels (CSC). In simple terms, timing channels rely on time synchronization, delays and related timing structures of a system for operation. A storage channel on the other hand rely on what is stored or can be stored in some memory for its operations.
Some time in the future, I will review the topic and provide examples as well as clear descriptions.
--- Sorry, I get to post something when I have a few minutes and that does not always allow for a coplete and comprehensive treamtment at a go. My expectation is that as I revisite the site and discovered uncompleted ideas or thoughts, I will update them. Also, when I have larger chunk of time on my hand I will develop the more complex ideas further and provide as much insight as possible into the workings of some of the technologies I allude to here.
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