Chapter 10: Securing TCP/IP Flashcards
Define: Integrity
The process that guarantees that the data received is the same as originally sent.
Define: Nonrepudiation
Means that a person cannot deny he or she took a specific action.
Define: Authentication
Means to verify that whoever is trying to access the data is the person you want accessing that data.
Define: Authorization
Defines what an authenticated person can do with the data.
Any encryption that uses the same key for both encryption and decryption is called:
symmetric-key encryption
Any encryption that uses different keys for encryption and decryption is called:
asymmetric-key encryption
Symmetric-key algorithms are either ____ ciphers or ____ ciphers.
block
stream
How do block ciphers encrypt data?
In single chunks of a certain length at a time.
How do stream ciphers encrypt data?
They take a single bit at a time and encrypt on-the-fly.
What is one serious weakness that symmetric-key encryption has?
Anyone who intercepts the key can encrypt or decrypt data with it.
How does asymmetric-key encryption solve the weakness of symmetric-key encryption?
The public key of the receiver is used to encrypt the symmetric-key before it is sent, and the receiver uses their private key to decrypt it.
Public-key cryptography, the primary asymmetric implementation, generates a key pair. What are these keys called?
private key
public key
What are the three asymmetric algorithms used today?
RSA (Rivest, Shamir, Adleman)
DSA (Digital Signature Algorithm)
ECDSA (Elliptic Curve DSA)
What is a one-way function that you run on a string of binary digits of any length that results in a value of some fixed length (often called a checksum or message digest)?
A cryptographic hash function
Can you recreate the original data from its hash if you know the hashing algorithm used?
No, a hash is irreversible.
How do operating systems and applications store passwords?
They only store the hashes of passwords and not the passwords themselves.
What is the primary family of cryptographic functions and which two are currently recommended?
SHA (Secure Hash Algorithm)
SHA-2 (six variants)
SHA-3 (six variants)
In network security, nonrepudiation is typically enabled by a combination of encryption and hashing called a:
digital signature
How does a sender of a message create a digital signature?
The sender hashes all or part of a message and then encrypts the hash with their private key.
The system for creating and distributing digital certificates issued by trusted third party certificate authorities (CA) such as DigiCert, GoDaddy, or Sectigo is called:
PKI (Public-Key Infrastructure)
What three things are included in a PKI certificate?
- Public Key
- Info about the certificate
- The digital signature of a trusted third party
In a PKI encryption method, which key encrypts the data?
The public key
In order to have a PKI you must have a/an ____.
root authority
What two jobs does a NAC (Network Access Control) application do?
- It usually prevents computers lacking anti-malware and patches from accessing the network.
- It creates policies that define what individual systems can do on the network.
