Domain 3 - Security Architecture and Engineering Flashcards
Caesar Cipher
Simple substitution cipher – Moved character 3 spaces
Subject to package analysis
Symmetric Vs Asymmetric
Symmetric - same key to encrypt and decrypt
Asymmetric - different keys to encrypt and decrypt
Vignere cipher
First polyalphabetic cipher
Enigma machine
used by Japan during WWII
PAIN of cryptography
PAIN Privacy Authenticity Integrity Non-repudiation
Initialization vector
Random bit string added that is the same length as the block size. XOR
Name a stream cipher
RC4
Symmetric
Relies on the use of a shared secret key
Pros -Fast -Good strong privacy Cons -out of band key distribution -doesn't scale well -does not provide non-repudiation
Symmetric cipher types
Stream
Block
Asymmetric cryptography
Every user has a key pair - private and public key
Asymmetric Algorithms
SA’s
E’s
DH
Asymmetric Algorithms
SA's RSA & DSA ECC & El Gamal DH (Dougie Houseer has a backpack) Diffie Hellman & Knapsack
Standard for digital signatures
RSA
What algorithm uses factorization
RSA
First asymmetric algorithm
Diffie Hellman
ECC
Elliptical Curve Cryptography
Based on points on a curve
Very efficient but only for key agreement (digital signatures)
Used on handheld devices
Usually the standard and answer for any Symmetric questions….
AES
Unless PGP then its IDEA
What keys are mathematically related
Asymmetric
Birthday attack
attempts to find collisions in hash functions
MD-5 how many bits
128
SHA-1 how many bits
160
SHA-2 how many bits
256, 384, 512….
Transposition cipher
uses an encryption algorithm to rearrange the letters of a plaintext message
Stream ciphers
Caesar - one
Vignere - word or sentence
One-time pad - key as long as the message itself
zero - knowledge proof
enables one to prove knowledge of a fact without revealing the fact itself
split knowledge
ensures that no single person has sufficient privileges to compromise the security of an environment
Work function/Work factor
Time and effort required to break a protective mechanism
DES and 3DES modes
Electronic Codebook Mode (ECB). Simplest and least secure
Cipher Block Chaining (CBC).
Cipher Feedback (CFB) .. uses chaining so error propagate
XOR Cipher
Flipping of bits
binary values match = 0
don’t match = 1
IPSEC two modes
Transport Mode
Tunnel Model
Protocols - Authentication Header (AH)
Encapsulating Security Protocol (ESP)
Replay attack
an attempt to reuse authentication requests
Security Models
Integrity (focus)
- Biba (State machine model)
- Clark-Wilson - access control triple—question is about lattice
- Goguen-Meseguer
Confidentiality
-Bell-LaPadula - no read up, no read down-state machine that enforces confidentiality..uses MAC to enforce security policy
- Brewer and Nash
- Take Grant
Bell LaPadula security model
Enforces confidentiality
Uses MAC to enforce DoD multilevel security policy (Gov)
Cannot read up
Cannot write down
Biba security model
Integrity
No read down
No write up
Clark-Wilson
Integrity
No read down
No write down
Take Grant model
confidentiality based
supports four basic operations - take, grant, create, and revoke
Brewer and Nash (Chinese Wall)
Confidentiality based
developed to prevent conflict of interest
Graham-Denning model
Focused on the secure creation and deletion of both data and subjects
Trusted Platform Module
Chip that resides on the motherboard chip
Access control types
Mandatory (MAC) - enforces policy that is determined by the system, not the object owner. Relies on classification labels.
Discretionary Access Control (DAC)
Permits the owner or creator of an object to control and define its accessibility
Non-discretionary access control
Enables the enforcement of system-wide restrictions that override object-specific access control.
Rule based access control
Usually found in firewalls
Role-Based Access Control
Uses well-defined collection of named job-roles that have specific permissions.
Techniques for ensuring CIA.
Confinement - restricts a process to reading from and writing to certain memory locations.
Bounds - limits of memory a process cannot exceed when reading or writing.
Isolation - the mode a process runs in when it is confined through the use of memory bounds.
