Secure Engineering Flashcards
Open/Closed System
Proprietary software, harder to integrate with.
Confinement
Allows process to w/r to only certain memory locations and resources. Sandboxing
Bounds
The area in memory/resources process can operate
Isolation
When process is confined when enforcing bounds
Mandatory Access Control
Static attributes of the subject/object are considered to determine access. RBAC
Discretionary Access Control
Subject has some ability to define objects to access. Access control list - dynamic access rule set that hte subject can modify. Often relates to subject’s identity
Trusted System
all protection mechanisms work together
Assurance
Degree of confidence in satisfaction of security needs
Trusted computing base
Hardware + software + controls to enforce security policy
Subset of system. Small as possible. Doesn’t require all other systems be trutsted.
Security perimeter -> trusted paths.
Reference monitor validates access to every resources prior to granting. Stands between every subj/obj
Security kernel: collection of components in TCB that implement RefMon functins
Orange Book
DoD 5200.28 / TCB
State Machine Model
Always secure no matter what state it’s in. Finite state machine, each state evaluate
Information Flow Model
Based on SMM. Bell-LaPdaula and Biba models.
Designed to prevent unauthorized/insecure/restricted info flow, often between ddiff levels of security.
Noninterference model
Concerned w/ how actions of subject at higher securit level affect system state of actions of a subject at a lower security level.
Composition Theories
Cascading / Feedback / Hookup
Cascading: input for sy1 comes from output of sys2
Feedback: sys2 provides feedback input to sys1
Hookup: sys1 sends info to sys2, another external system
Take-Grant model
Directed graph how rights can be passed from one subject to another from a subject to an object.
Take rule, Grant Rule, Create Rule, Remove rule
Access Control Matrix
Table of subjects and objects indicating which actions the subject can perform.
Each column is an ACL. Each row is a capabilities list
Bell-LaPaluda Model
Focused on maintaining confidentiality. State machine model security
Simple Security Property: no read up
* security property: no write down (confinement property)
Discretionary security property: Access matrix to enforce DAC
Biba model
Addresses integrity. State machine model concept. Commercial orgs
Simple Integrity Prop: no read-down
* Integrity Property: no write-up
Drawbacks: only integrity (no CA). No internal threat handling. No access control mgmt. Doesn’t prevent covert channels
Clark-Wilson model
Commercial application. Subject/program/object (triple). Subjects access objects through programs. Integrity.
- Constrained Data Item
- Unconstraited data item.
- Integrity verification procedure
- Transformation procedures. only procedures allowed to modify a CDI.
Security labels. Restricted interface model.
Brewer and Nash (Chinese Wall) model
Puts a ‘wall’ around data from domains in the same conflict class.
At moment of action, access to any conflicting data is temporarily blocked.
Goguen-Meseguer Model
Integrity model. Noninterference theories/model. Users can only perform predetermined actions on predetermined objects
Sutherland Model
Integiry model. SMM + info flow model. Defines a set of system states, initial states, and state transitions…
Graham-Denning Model
Secure creation/deletion of subjects and objects.
Rules for: create and object/subj, delete and obj/subj, provide read/grant/delete/transfer access.
Usually defined in an Access Control matrix
TCSEC
repealed and replaced by Common Criteria. Orange book. Focused on confidentiality
Trusted Computer System Evaluation Criteria. Part of Rainbow Series
Categories:
- A: verified protection. Highest level of security
- B: mandatory protection
- C: discretionary protection
- D: minimal protection. Reserved for systems that have been evaluated but do not meet other category requirements
Levels
- D: Minimal Protection
- C1: Discretionary Protection
- C2: Controlled Access Protection
- B1: Labeled Security
- B2: Structured protection
- B3: Security domains
- A1: Verified protection
