Revision Flash Cards
A __________ is any action that compromises the security of information owned by an organization.
security attack
An original intelligible message fed into the algorithm as input is known as _________ , while the coded message produced as output is called the __________.
plaintext, ciphertext
The methods of __________ conceal the existence of the message in a graphic image.
steganography
__________ involves the passive capture of a data unit and its subsequent retransmission to produce an unauthorized effect.
replay
If both sender and receiver use the same key, the system is referred to as ___________ encryption.
conventional
A __________ attack involves trying every possible key until an intelligible translation of the ciphertext is obtained.
brute-force
A way to improve on the simple monoalphabetic technique is to use different monoalphabetic substitutions as one proceeds through the plaintext message. The general name for this approach is ___________ .
polyalphabetic substitution cipher
__________ techniques map plaintext elements (characters, bits) into ciphertext elements.
Substitution
_________ refers to the use of multiple, overlapping protection approaches addressing the people, technology, and operational aspects of information systems.
Layering
A common technique for masking contents of messages or other information traffic so that opponents can not extract the information from the message is ___________
encryption
Triple-DES with two keys encryption uses the formula:
C = E(K1, D(K2, E(K1, P)))
The output of the encryption function is fed back to the shift register in the ________ mode.
OFB
__________ seeks to make the relationship between the statistics of the ciphertext and the value of the encryption key as complex as possible so that even if the attacker can get some handle on the statistics of the ciphertext, the way in which the key was used to produce that ciphertext is so complex it is difficult to deduce the key.
Confusion
In the general structure of AES, the input to the encryption and decryption algorithms is a single _________ block.
128-bit
The __________ is when a small change in plaintext or key produces a large change in the ciphertext
avalanche effect
CFB does not conform to the typical construction of a stream cipher because:
the bit stream it generates depends on the plaintext
The encryption round in AES has the structure:
SubBytes, ShiftRows, MixColumns, AddRoundKey
A __________ cipher is one that encrypts a digital data one bit or one byte at a time.
stream
Allowing for the maximum number of possible encryption mappings from the plaintext block is referred to by Feistel as the __________ .
ideal block cipher
The _________ and _________ block cipher modes of operation are used for authentication.
CBC, CFB
Asymmetric encryption can be used for __________ .
both confidentiality and authentication
The Secure Hash Algorithm (SHA) is based on _____.
MD4 hash function
Due to the birthday paradox, for an m-bit hash value and randomly picked data blocks, we can expect to
find two data blocks with the same hash value within ________ attempts.
2m/2
Using RSA algorithm, if p = 11, q = 19, e = 13, and M = 5, then C = ______.
169
The communication between A and B in the form A→B: E(K, [M||E(PRa,H(M))]) provides ____________.
both confidentiality and digital signature
If two users, A and B, use Diffie-Hellman key exchange, which of the following values is NOT shared between A and B?
Xa
