Domain 3: Security Engineering and Architecture Flashcards
Common Criteria
Structured methodology for documenting security requirements, documenting and validating. Based on ISO 15408
Protection Profile
Specifies the security requirements and protections of a product that is to be evaluated. Organised around TCB entities. Evaluation Assurance Levels (EAL)
Evaluation Assurance Levels (EAL)
EAL0 - Inadequate assurance
EAL1 - Functionally tested
EAL2 - Structurally tested
EAL3 - Methodically tested and checked
EAL4 - Methodically designed, tested, and reviewed
EAL5 - Semi formally designed and tested
EAL6 - Semi formally verified design and tested
EAL7 - Formally verified design and tested
Target of Evaluation (TOE)
The target for the product
Protection Profile (PP)
Set of security requirements of TOE
Security Functional Requirements (SFRs)
Specific individual security functions
Engineering principles for IT Security
Use NIST SP 800-27
- Initiation; need expressed, purpose documented, impact assessment
- Development/Acquisition; system designed, purchased, programmed, developed or constructed
- Implementation; system tested and installed, certification
- Operation/Maintenance; performs function, security operations, audits
- Disposal; disposition of information, HW and SW
Physical controls are your first line of defense, and people are your last
OS Kernel
Loads and runs binary programs, schedules task swapping, allocated memory and tracks physical location of files on computers hard disk, manages IO/OP requests from software, and translates them into instructions for CPU
Primary storage
Temporary storage area for data entering and leaving the CPU
Random Access Memory
Temporary holding place for data used by the OS. It is volatile. Two types of RAM exist: Dynamic and Static. Dynamic RAM needs to be refreshed periodically, while Static RAM’s data does not need to be refreshed
ROM
Read only memory is non-volatile which means when a computer is turned off the data is not lost. EEPROM can be altered
Process States
- Stopped: process finishes or must be terminated
- Waiting: the process is ready for continued execution but is waiting for a device or access request
- Running: executes on the CPU and keeps going until it finishes; its time slice expires, or it is blocked
- Ready; process prepared to executve when CPU ready
Multitasking
Execute more than one task at the same time
Multitasking
More than one CPU is involved
Multiprocessing
More than one CPU is involved
Multi-Threading
Execute different parts of a program simultaneously
Single state machine
Operates in the security environment at the highest level of classification of the information within the computer. In other words, all users on that system must have clearance to access the info on that system.
Multi state machine
Can offer several security levels without risk of compromising the system’s integrity
CICS
Complex instructions. Many operations per instruction. Less number of fetches
RISC
Reduced instructions. Simpler operations per instructions. More fetches
Generations of Software
1st Gen: Machine Language 2nd Gen: Assembler 3rd Gen: FORTRAN: C++ 4th Gen: Natural/focus and SQL 5th Gen: Prolog, list artificial intelligence languages based on logic
Memory Segmentation
Dividing memory into segments
Protection Keying
Numerical values, divides physical memory up into particular sized blocks, each of which has an associated numerical value called a protection key
Paging
Divides memory address space into even sized blocks, called pages. To emulate that we have more RAM than we have. System kernel knows the location of the page file.
DEP
Data Execution Prevention: A system level memory protection feature that is built into the OS DEP prevents code from being run from different pages, such as default heap, stacks, and memory pools
ITIL
Best practices for IT operations, including change management and configuration management.
Security Models
Defines allowed interaction between subjects and objects at a particular moment in time
State Machine Model
Describes a system that is always secure no matter what state it is in. If all aspects of a state meet the requirements of the security policy, that state is considered secure. A transition occurs when accepting input or producing output. A transition always results in a new state (also called a state transition). A secure state machine model always boots into a secure state, maintains a secure state across all transitions, and allows subjects to access resources only in a secure manner compliant with the security policy.