Stanford Foundations of Information Security XACS101 1.1 - Security Goals
Notes from section 1.1 - Security Goals of Stanford Foundations of Information Security XACS101 Course.
Security is Holistic
Hackers start with the simplest thing possible.
- Physical
- Limit access to physical spaces includes offsite Data Centers
- Dumpster diving - shred sensitive documents
- Technological
- Application Security e.g.:
- No flaws in identity verification process
- server configured correctly
- Interpret data robustly
- OS
- Network Security
- Mitigate malicious traffic
- Firewalls and Intrusion Detection Systems
- Policies and Procedures
- e.g. Phishing/Social Engineering
- Sneaking in tail gators
- Fixed through Education eg. never give out your password
- Application Security e.g.:
Authentication - Who are you talking to
Goals
Verify Identity - Three Ways:
- Something you Know (Passwords)
- One-time Passwords (OTP)
- Something you Have (Token)
- Strength depends on difficult of forging
- Something you Are (Biometrics)
- Palm scans for most effective
- Has false positives and false negatives
- false positive - authentic user rejected
- false negative - imposter accepted
- Key management harder i.e. you can’t issue a new finger
Three types:
- Server authentication - verifying cert
- Client authentication - logging in
- Mutual - both
Authorization - Has permission to conduct action
Access Control List - e.g. Unix permission model
Access Control Model:
- Mandatory - computer decides who can do what
- Discretionary (unix) - users authorized to determine access
- Non-Discretionary- determined by role
Bell-LaPadula Model
- Classifications - Top Secret, Secret, Classified, Unclassified
- 3 Rules/Properties
- Simple Property (no read up) - can’t access files with higher classification
- Property (confinement) (no write down) - prevent information leakage - only people with at or greater classifications can see documents you create
- Tranquility property - object can’t change classification level unless there are no other readers or writers
**2 Side Note: Biba Integrity Model
Confidentiality - keep contents secret
-
Encryption/crypo
-
Access Controls
Data Integrity
- Man in the Middle Attack
- Integrity Checks - Using Hashing Functions/Checksum
- Message Authentication Code (MACs) like Checksum w/ keys (SSL uses this)
- e.g. TCP/IP
Accountability
- Who performed action
- Logging/Audit Trails
- Make sure to use secure logging w/ time stamping
- Data integrity in logs, can’t be able to change logs
- WORM device - write once, read many
Availability
- Uptime
- Have redundancy
- DDoS
Non-Repudiation
- Undeniability of transaction
- Usually involves 3rd party (not bitcoin)
- Generate evidence e.g. receipts (need to be digitally signed) - Side Note: Interesting to create software to handle this.
Acronyms:
- AAA - Authentication, Authorization, Accountability
- CIA - Confidentiality, Integrity, Availability
Further study:
- MACs
- Bell-LaPadula Model