quiz2-week 3 content Flashcards
what is cryptography
Scrambling information so it cannot be read
* Transforms information into secure form so unauthorized persons cannot access it
what is Steganography
- Hides the existence of data
where can data be hidden in image, video and audio files
header fields and metadata
what is encryption
is the process of changing original text into a secret message using
cryptography
what is plaintext
s unencrypted data to be encrypted or is the output of decryption
ciphertext is
is the scrambled and unreadable output of encryption
cleartext data is
is data stored or transmitted without encryption
plaintext data is input into a
is input into a cryptographic algorithm (also called a cipher)
A key is a ___ ___ entered into the algorithm to produce ____
* The reverse process uses the key to decrypt the message
mathematical value
ciphertext
A substitution cipher substitutes one ___ for ____
one character for another
ROT13 meaning
rotate alphabet 13 steps clockwise
xor cipher compares two ___,
if they are different, __ is returned
bits
1
Cryptography can provide several basic protections
___
___
___
___
___
Confidentiality ensures only authorized parties can view it
- Integrity ensures information is correct and unaltered
- Authentication ensures sender can be verified through cryptography
- Nonrepudiation proves that a user performed an action
- Obfuscation is making something obscure or unclear
security through obscurity
definition
example
An approach in security where virtually any system can be made secure as long as
outsiders are unaware of it or how it functions
using port 70 instead of port 80
Cryptography can provide protection to data as that data resides in any of three states:
* Data in ____ (also called data in use) is data actions being performed by “endpoint
devices”
* Data in _____ are actions that transmit the data across a network
* Data at ____ is data that is stored on electronic media
processing
transit
rest
___ vs ___ constraint is a limitation in providing strong cryptography due to the
tug-of-war between available resources (time and energy) and the security provided by
cryptography
resource vs security
It is important that there be___ ___in cryptography
* is the ability to quickly recover from these resource vs. security
constraints
high resiliency
Which of the following is a term that proves that a user performed an action with a computer or
on data?
a. Confidentiality
b. Nonrepudiation
c. Obfuscation
d. Authentication
b
Three categories of cryptographic algorithms
* ___algorithms
* ____cryptographic algorithms
* ____cryptographic algorithms
Three categories of cryptographic algorithms
* Hash algorithms
* Symmetric cryptographic algorithms
* Asymmetric cryptographic algorithms
A fundamental difference in cryptographic algorithms is the ___ of __ __ at a
time
* ____ cipher - takes one character and replaces it with another
* ___ cipher - manipulates an entire block of plaintext at one time
* ___ function - takes as input a string of any length and returns a string of any
requested variable length
amount of data processed
stream
block
sponge
Hash algorithm creates a unique “___ ___” of a set of data and is commonly called
hashing
* This fingerprint, called a ___ (sometimes called a message ____ or hash), represents
the contents
digital fingerprint
digest
Hashing is intended to be __ ___in that its digest cannot be reversed to reveal the original
set of data
one way
Secure hashing algorithm characteristics:
- ___ ___ - short and long data sets have the same size hash
- ___ - two different data sets cannot produce the same hash
*___ - data set cannot be created to have a predefined hash
- ___ - resulting hash cannot be reversed to determine original plaintext
fixed size
unique
original
secure
SHA-____ is currently considered to be a secure hash
* SHA-____ was announced as a new standard in 2015 and may be suitable for low-power
devices
SHA-2 is currently considered to be a secure hash
* SHA-3 was announced as a new standard in 2015 and may be suitable for low-power
devices
____ cryptographic algorithms use the same single key to encrypt and decrypt a
document
Symmetric
________ cryptographic algorithms use two mathematically related keys
types of keys
Asymmetric
public
private
Digital Signature Algorithm (DSA)
* Creates a _____ ___ - an electronic verification of the sender
Digital Signature Algorithm (DSA)
* Creates a digital signature - an electronic verification of the sender
Which of the following is a function of a digital signature?
a. Provides authorization
b. Encrypts transmitted data
c. Decrypts transmitted data
d. Proves message integrity
d
A digital signature can verify the sender of data, prevent a sender from disowning a
message, and prove message integrity.
Two of the most common cryptography attacks are ____ attacks and ____ attacks
Two of the most common cryptography attacks are algorithm attacks and collision attacks
