Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CISSP > Chapter 7 - Crypto > Flashcards

Chapter 7 - Crypto Flashcards

0
Q

Monoalphabetic vs polyalphabetic

A

Mono - one alphabet

Poly - many alphabets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Substitution cypher

A

Replacing a letter for each letter with a predetermined one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cipher

A

Algorithm or key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Scytale cipher

A

A piece of paper wrapped around a staff that could only be viewable on the correct size staff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Project lucifer

A

The original IBM project that NSA used to make DES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cryptanalysis

A

Analyzing an encryption trying to figure out the key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Crypto system

A

A system that creates a crypto

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cryptovariable

A

The key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Key space

A

This is how large the key is in bits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Kerchiefs principle

A

Algorithm of a crypto system should always be known, only the key should be secret, others believe it should all be secret.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What gives a cryptosystem strength?

A 
Algorithm
Key length
Secrecy
Initialization
Interoperability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Work factor

A

The length of time it will take to discover a message by brute force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Crypto offers what benefits?

A 
Confidentiality
Integrity
Authentication
Authorization
Nonrepudiation - cannot deny it came from the sender
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Encipher

A

Making data unreadable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Vernam cipher - one time pad

A

DUO could be an example of this..

Exclusive-OR (XOR) - if different than 1 if same than 0

Message - 1001
Key - 1100 (same length as message)
Ciphertext - 0100

Only useful one time to not develop patterns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Rules of crypto as I see it

A

Key - keep it secret, keep it safe
Random - computers are NOT random
Cipher - the word “the” is your enemy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Running key cipher

A

Physically analyzing data like the letter in a book with coordinates

Running to piece to piece to get the answer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Concealed cipher

A

Every third word is part of the message

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Steganography

A

Hiding messages within other media .. Ex. Inside the Theodore jpg image

Security through obscurity.. Yikes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Least significant bit - LSB

A

These are the bits in the medium that do not affect the output, a perfect place to hide a message

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Digital watermarking / DRM

A

Uses stenography to embed a logo or company specific information in the data using the LSB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Microdot

A

A micro photo put inside the wax of a stamp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Caesar cipher

A

Substitution cipher, a=z

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Transposition cipher

A

Word grouping and scrambling based on a key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do algorithms work within a cipher?

A

They are substitution and transposition methods randomized into several different sequence functions

Many algorithms to choose from, the key chooses the algorithms to use per message

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Frequency analysis

A

E is the most common letter, the most common 8bit sequence therefor equals E

The comes next and so forth so on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

KDF - key derivation function

A

This is the master key that creates all other subkeys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

N(N-1)/2

A

Formula for # symmetrical keys needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Out of band method

A

Using a completely separate media to transfer the key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Symmetrical key

A

Shared secret key

Pros:
Fast!
Hard to break
Confidentiality

Cons:
Requires secure delivery of key
Each pair needs unique key
No authenticity or nonrepudiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Examples of symmetric algorithms

A 
DES
3DES
Blowfish
IDEA
RC4,5,6
AES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Asymmetrical key

A

PKI - private / public keys

Private to public is open message format as anyone can open the message

Public to private is secure message format because only the intended person can open it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the pros and cons of asymmetrical algorithms?

A

Pros:
Better key distribution
Better scalability
Can provide authentication and nonrepudiation

Cons:
Slow. . .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Examples algorithms for asymetrical keys

A 
RSA
DH
ECC
El Gamal
Merkle-Hellman Knapsack
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Block ciphers

A

A chunk of data is encrypted at a time in a block (s-box) of 32/64/128

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Confusion vs diffusion

A

Substitution vs transposition respectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Avalanche effect

A

One bit change can cause all the cipher text to change or as close as possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Stream cipher

A

XOR based encryption but by bit using a keystream generator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Initialization vector

A

Randomness within the algorithm, cause a pattern in the plaintext to not cause a pattern in the cryptotext

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Strong stream cipher characteristics

A

Long periods of no pattern repeat
Statistically unpredictable
Key stream is unrelated to key
Same number of 0’s and 1’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Stream vs block

A

Stream is fast and less secure

Block is slower but more secure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Compression

A

Compression will cause redundancy to be reduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Expansion

A

Expanding the plaintext to the key size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Padding

A

Adding material to make it more difficult to know what is legitimate message

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Key mixing

A

This is just a subkey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Block ciphers

A

A chunk of data is encrypted at a time in a block (s-box) of 32/64/128

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Confusion vs diffusion

A

Substitution vs transposition respectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Avalanche effect

A

One bit change can cause all the cipher text to change or as close as possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Stream cipher

A

XOR based encryption but by bit using a keystream generator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Initialization vector

A

Randomness within the algorithm, cause a pattern in the plaintext to not cause a pattern in the cryptotext

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Strong stream cipher characteristics

A

Long periods of no pattern repeat
Statistically unpredictable
Key stream is unrelated to key
Same number of 0’s and 1’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Stream vs block

A

Stream is fast and less secure

Block is slower but more secure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Compression

A

Compression will cause redundancy to be reduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Expansion

A

Expanding the plaintext to the key size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Padding

A

Adding material to make it more difficult to know what is legitimate message

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Key mixing

A

This is just a subkey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Public key cryptography

A

A hybrid approach using both asymetrical and symetrical algorithms

Asymetrical to encrypt the symetrical key and symetrical to encrypt the message

Private to public is nonrepudiation
Public to private is confidentiallity

57
Q

Digital envelope

A

More common name for hybrid crypto approach.

58
Q

What is the NSA version of DES?

A

DSA - data encryption algorithm - 56 bit intentionally weakened to 128 bit

59
Q

What is the replacement for DES?

A

Rijndael - AES

60
Q

How does DES work?

A

64 bit block goes in 64 bit block comes out..

61
Q

What are the modes of symmetrical encryption?

A 
Electronic code book ECB
Cipher block chaining CBC
Cipher feedback CFB
Output feedback OFB
Counter mode CTR
62
Q

Electronic code book

A

Translative 1:1 cipher goes in hdkfjr comes out every time in 64 bit blocks

This is easily reverse engineered and stolen

63
Q

Cipher block chaining

A

Plaintex 1 to ciphertext1 using IV
Plaintext2 to ciphertext2 using ciphertext1

Changing the Initialization Vector per message will assist in randomness
Processes 64 bit blocks at a time

64
Q

Cipher feedback

A

Similar to stream cipher, uses an IV and a key to choose an algorithm generating the key stream and cipher text

The difference is in CFB the next block of plaintext uses the key and the last ciphertext to feed the key stream

65
Q

Output feedback

A

This is exactly like cipher feedback except the key stream is used instead of the cipher text on the next plaintext block

It does not rely on the data for the crypto therefor corrupt data will not affect the output

66
Q

Synchronous vs asynchronous cipher

A

Synchronous is stream/block

Asynchronous is chaining

67
Q

3DES

A

Uses 48 rounds of encryption chaining to force random into the ciphertext

This was a quick fix until AES could be ratified using Rijndael

68
Q

What does DES-EDE2 actually mean?

A

DES is used to encrypt plaintext with the first key the decrypt with a different key then encrypt that with the original key

69
Q

What is IDEA?

A

IDEA is 64 bit block broken in 16 block chunks for processing

IDEA is an algorithm used in RSA

70
Q

PGP

A

Software used to encrypt mail and files at rest

71
Q

Blowfish

A

Block cipher with 32 - 448 bit key lengths and is completely open to the public

72
Q

RC4

A

Very common stream cipher used in SSL and WEP

73
Q

RC5

A

Highly variable round size, key size and block size..

74
Q

RC6

A

RC5 but faster

75
Q

What does rc5-32/12/16 mean?

A

Rc5
32 bit words or 64 bit encryption
12 rounds
16 byte key (128 bit)

76
Q

Diffe-Hellman

A

Asymetrical key

A combines A’s private and B’s public keys to make a shared key

B combines B’s private and A’s public key to derive the same shared key

77
Q

How can Non authenticated DH be broken by man in the middle?

A

Man in the middle generates two shared keys in either direction of the communication

78
Q

RSA

A

An algorithm devised by multiplying two 2^300 prime numbers (numbers only divisible by themselves or 1) times the random encryption key.

One side does encryption one side does signatures each other side does the inverse

79
Q

Key exchange vs key agreement?

A

Exchange means it needs to be shared from one side to the other

Agreement is when the keys are calculated on each side independently to be the same value

80
Q

Trapdoor

A

This is the easiest way to solve for a crypto algorithm, in RSA this is to factor the large numbers

81
Q

One way function

A

Easy to calculate hard to solve for

Like breaking a glass and putting it back together again

82
Q

El Gamal

A

Extension of DH but slowest of the asymmetric algorithms

83
Q

Elliptical curve cryptography

A

Uses an elliptical curve based on the encryption key to quickly get the values need for the crypto

Very fast, with small keys, used in mobile devices

84
Q

Knapsack

A

Insecure Crypto based on the knapsack problem in math

85
Q

What is zero knowledge proof?

A

Giving people only the information they need and nothing more and is relevant in private key to public key crypto

86
Q

One way hash

A

Appended to the end of the message to ensure integrity

This is also called a message digest

87
Q

What is a MAC in terms of hash and crypto

A

Message authentication code

It is used to protect message integrity
Uses a symmetric key to encrypt a message digest to ensure man in the middle has not occurred

88
Q

HMAC

A

A symmetric key is appended to the message and the message is hashed with it together

89
Q

CBC-MAC

A

Encrypts message, uses the final block of code as MAC value appended to a message

90
Q

MAC offers system protection, what is this?

A

Data origin protection, you know the person who sent it had the symmetric key and is the weakest for of authentication

91
Q

Should the same key be used for authentication and encryption?

A

NO

92
Q

What is the block cipher MAC called

A

CMAC, same as CBC-Mac with a bit more complexity

93
Q

CCM

A

Combines CMAC and CBC-MAC

CMAC for the encryption and the IV for the CBC-Mac

94
Q

What is a collision free hashing algorithm?

A

This means no two messages can give the same hash value

95
Q

MD2 MD4 MD5

A

Message Digest 2 - 128bit hash slowly
MD4 - 128 bit fast
MD5 - 128 bit fast and complex

None are suitable to prevent collision

96
Q

SHA

A

160 bit message digest using an asymmetrical algorithm like Diffe-Hellman

97
Q

HAVAL

A

Variable length modification to MD5

98
Q

Tiger

A

Most notably a 192 bit message digest not using the MD4 architecture and does not use IVs

99
Q

Birthday attack

A

It is easy to find two matching values I a sea of values than to find a match for a specific value, it’s a statistics problem

Meaning that 2^n/2 where n is the bit rate of the message digest is the number of attempts needed to find a duplicate of the hash value

100
Q

Digital signature

A

Message digest encrypted by a private key giving both integrity and norepudiation

101
Q

Registration Authority

A

Verifies the user is who they say they are

102
Q

Cross certification

A

CA one trusts CA two and each acts as the other would

103
Q

What is a certificate revoke list and online certificate status protocol?

A

CRL is the list of dead certificates

OCSP is the method to check when you enter a site

104
Q

X.509

A

Certificate building standard, v3 is the most common.

105
Q

How is the private key issued from as certificate authority?

A

It isn’t, the CER you submit has public key the certificate is made from, this public key is based off the private key generated from your machine

106
Q

PKI offers what security services?

A 
Confidentiality
Access control
Integrity
Authentication
Nonrepudiation

But not all at once, it depends on the direction and these are specifically for the slow asymmetrical encryption of the symmetric keys

107
Q

Key escrow

A

This is the process or person who can recover a lost key

108
Q

Multiparty key recovery

A

Requirement of 2 or more people in order to reassemble a key, this forces collusion to compromise

109
Q

Trusted platform module

A

A hardware technology for encrypting, particularly hard drives. Provides sealing which is a hash of the configuration files to verify integrity

110
Q

Link encryption vs end-to-end encryption ?

A

Link is with headers encrypted and is considered traffic flow security
End to end is just the data encrypted

111
Q

What is MIME?

A

A mime type is a way to differentiate handling data types .txt is type/plaintext

112
Q

S/MIME

A

Uses PKI for email encryption

113
Q

What is a web of trust ?

A

Each request generates a public trust .. I give you my public key for yours and now we trust each other

114
Q

Where are the public keys stored on PGP?

A

A key ring

115
Q

What is the difference between SSL and TLS?

A

TLS is the open standard

116
Q

What is secure electronic transaction ETS?

A

A superior technology of securing credit card data that requires participation and implementation from merchant, bank and vendor, not used much due to complexity .. SSL is still the standard

117
Q

What is the primary purpose of a cookie?

A

To make stateless HTTP act more stateful.

This is how even though you close a browser your items stay in the cart..

118
Q

How do I make a timeout page with cookies?

A

Have the client loaded web page check cookies client side periodically for session authenticity.

Cookies have timeouts.

119
Q

IPSec

A

Used to establish a server to server VPN tunnel

120
Q

What are the two security protocols and what do they do for IPSec?

A

Authentication header AH- does auth only

Encapsulating security payload ESP - does auth and crypto

121
Q

What modes does IPSec work in?

A

Transport mode - payload encryption

Tunnel mode - routing/header/payload encryption

122
Q

What is a security association SA?

A

A directional (out/in) store for the encryption keys and configurations used in an IPSec tunnel

123
Q

How does a security parameter index assist in IPSec VPN?

A

These are used to organize and globally configure the SA for each device outbound and inbound separately

124
Q

What is an ICV?

A

Basically just a hash, AH does the entire packet, ESP does just the data/transport for integrity

125
Q

How is IKE used in IPSec?

A

As a key management architecture

ISAKMP is infrastructure
OAKLEY is the worker

126
Q

Passive vs active attack

A

Passive is just listening

Active is actually modifying

127
Q

Ciphertext only attack

A

Sniffing the ciphertext and trying to decode it

128
Q

Known plaintext attack

A

I know this message starts with to:
And I see every message start with cypher text zxs

Zxs must be to:

129
Q

Chosen-ciphertext attacks

A

I send you a note of importance in plaintext you feel compelled to send to others encrypted, I sniff the encrypted output and have a direct correlation

130
Q

Chosen-ciphertext

A

I have cypher text part and the plaintext whole, where does it match?

131
Q

Differential cryptanalysis

A

Figuring out which algorithms are more likely to run within a cryptosystem

132
Q

Linear cryptanalysis

A

Sensing plaintext into an algorithm many ones to discover a pattern in s boxes chosen

133
Q

Side channel attacks

A

Attacks using non mathematical means , like power voltage consumption

134
Q

Replay attack

A

Capturing data and resubmitting it

135
Q

Algebraic attack

A

Using mathematical principles to discover information, like 0 times something is always 0

136
Q

Analytic attack

A

Isolated specific flaws in the algorithm to attack (double DES died this way)

137
Q

Statistical attack

A

Checking for more 1 than 0, could identify the use of a weak random number generator

138
Q

Social engineering attack

A

Persuasion, coercion, or bribery used to get keys

139
Q

Meeting in the middle attack

A

Tries to match the decryption to the encryption by attacking both sides at the same time

CISSP (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions