TRUSTED SYSTEMSNetwork Security And Cryptography

By:-  SUMITA DAS

Created by Sumita Das

TRUSTED SYSTEMS

To enhance the ability of a system to defend against-Intrudersmalicious programs.

Created by Sumita Das

DATA ACCESS CONTROLAccess Matrix:

SubjectObjectAccess right

Created by Sumita Das

DATA ACCESS CONTROL

Access Control List: Decomposition of the matrix by columns

Created by Sumita Das

DATA ACCESS CONTROL

Capability list: Decomposition of the matrix by rows

Created by Sumita Das

TRUSTED SYSTEMS CONCEPT Protect data and resources on the basis of levels ofsecurity.

Unclassified(U)Confidential(C)Secret(S)Top Secret(TS)

Created by Sumita Das

SECURITY LEVELS

Multilevel security: Multiple categories or levels of data

Multilevel secure system must enforce:No read up (Simple Security Property)No write down(Property)

Security levels may be linear or latticed

Created by Sumita Das

REFERENCE MONITOR

Provides multilevel security for a data processing system

Controlling element in the hardware and operating system of a computer that regulates the access of subjects to objects on the basis of security parameters of the subject and object.

Created by Sumita Das

Created by Sumita Das

REFERENCE MONITOR PROPERTIES

Complete mediation Isolation Verifiability

Created by Sumita Das

EXAMPLE: TROJAN HORSE DEFENSE

Secure, trusted operating systems are one way to secure against Trojan Horse attacks

Created by Sumita Das

REFERENCES

[1]William Stallings, “Cryptography and Network Security Principles and Practices”, Fourth Edition