Networking
Systems
Encryption
PKI and TLS
Misc
100
List the layers of the OSI 7-Layer model
7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data-Link
1. Physical
100
List the four fundamental components of a computer.
Processor
Primary Storage
Secondary Storage
Networking
100
What is the fundamental difference between asymmetric and symmetric encryption?
Number of keys.
Asymmetric uses different keys to encrypt and decrypt a single message.
Symmetric only uses one.
100
Who signs the certificate of a Trusted Root Certificate Authority
The CA signs its own certificate
100
What is an error at OSI Layer 8?
8 is referred to as the social layer. An error indicates some human error in performing tasks or administration
200
List the three responsibilities of the Presentation Layer.
Encoding, compression, and encryption
200
What is a "distribution" of Linux?
An Linux OS pre-packaged and pre-configured with OS customization/addons and user applications/utilities.
200
Provide one similarity and difference between encryption and hashing.
Similar in data obfuscation.
However, hashing should not be reversible and is typically less computationally expensive.
200
List four categories of information that can be included in a cipher suite.
- Key agreement method
- Symmetric encryption algorithm or data transfer encryption algorithm
- Asymmetric Encryption Algorithm or authentication/signature
- Hashing Algorithm
200
Define the "Next-Hop" in a network route.
Next-Hop refers to the next networking device at a certain OSI layer that the message should be passed to in order to reach final destination.
300
Describe two methods of multiplexing at the Physical Layer.
FDM: Assigning unique frequency ranges to multiple conversations
WDM: Optical mediums, assigning light wavelength to conversations
TDM: Granting access to medium in certain time intervals
CDM: Orthogonal encoding to combine data at bit level
300
The root domain
300
Identify which asymmetric keys are used to encrypt and decrypt messages when to goal is:
1. Confidentiality
2. Authenticity
Alice sends message to Bob.
Confidentiality: encrypt with BPub and decrypt BPriv
Authenticity: encrypt with APriv and decrypt APub
300
At what point in TLS handshake can symmetric-encrypted messages be sent?
As soon as ChangeCipherSpec message is sent
300
List the three main methods of authentication
1. Something you know
1. Something you have
2. Something you are
400
Provide the following for the network 56.100.3.24/29:
- Network Address
- Broadcast Address
- Subnet Mask
- Number of Usable Hosts
Network Address: 56.100.3.24
Broadcast Address: 56.100.3.31
Subnet Mask: 255.255.255.248
No. of Usable Hosts: 6
400
Where is the hypervisor located in hosted vs bare-metal virtualization
Hosted: As an application on top of host operating system
Bare-Metal: directly on top of the hardware
400
What math problems do the following signature algorithms rely on for key security:
1. DSA
2. RSA
1. Discrete Logarithm problem
2. "Factoring Problem" - factoring large semiprime
400
What two responsibilities are we "trusting" a Certificate Authority with in PKI?
1. Authenticate entities the CA signs for
2. Protect own private keys
400
Describe difference between signature and heuristics-based security.
Signature: use defined Indicator of Compromise to identify conditions for malicious activity
Heuristics: Look for abnormal behavior, relies on a baseline
500
Subnet the network 192.168.8.0/22 into networks that can support:
- 300 hosts
- 127 hosts
- 10 hosts
Provide network addresses and CIDR values
192.168.8.0/23
192.168.9.0/23
192.168.10.0/28
500
List five responsibilities of an Operating System
File & Data Management
Memory Management
Device Management
Process Management
Fault Management
Security
Communication/Networking
500
Describe the security concerns with the above encrypted image and what caused it.
Encryption algorithm did not introduce enough randomness. The data is somewhat recognizable in ciphertext.
500
What symmetric cryptography tool provides authentication and integrity in a message similar to a digital signature?
Hash-Based Message Authentication Code
or
Keyed-Hash Message Authentication Code
500
Describe Perfect Forward Secrecy
Data will remain confidential in the future even if key material is compromised