Quiz questions Flashcards
The firewall may be a single computer system or a set of two or more systems that cooperate to perform the firewall function.
true
A firewall can serve as the platform for IPSec.
true
A packet filtering firewall is typically configured to filter packets going in both directions.
true
A prime disadvantage of an application-level gateway is the additional processing overhead on each connection.
true
A DMZ is one of the internal firewalls protecting the bulk of the enterprise network.
false
The _______ defines the transport protocol.A. destination IP address B. source IP address C. interface D. IP protocol field
D
A _________ gateway sets up two TCP connections, one between itself and a TCP user on an inner host and one between itself and a TCP user on an outside host.
circuit-level
Typically the systems in the ________ require or foster external connectivity such as a corporate Web site, an e-mail server, or a DNS server.
DMZ
A _______ configuration involves stand-alone firewall devices plus host-based firewalls working together under a central administrative control.
Distributed firewall
The ________ attack is designed to circumvent filtering rules that depend on TCP header information.
tiny fragment
Intrusion detection is based on the assumption that the behavior of the intruder differs from that of a legitimate user in ways that can be quantified.
true
To be of practical use an IDS should detect a substantial percentage of intrusions while keeping the false alarm rate at an acceptable level.
true
An inline sensor monitors a copy of network traffic; the actual traffic does not pass through the device.
false
A common location for a NIDS sensor is just inside the external firewall.
true
Network-based intrusion detection makes use of signature detection and anomaly detection.
true
Symmetric encryption is used primarily to provide confidentiality.
true
Two of the most important applications of public-key encryption are digital signatures and key management.
true
The secret key is one of the inputs to a symmetric-key encryption algorithm.
true
The strength of a hash function against brute-force attacks depends on the length of the hash code produced by the algorithm.
true
Public-key algorithms are based on simple operations on bit patterns.
false
A _______ monitors the characteristics of a single host and the events occurring within that host for suspicious activity.
host-based IDS
_______ involves an attempt to define a set of rules or attack patterns that can be used to decide if a given behavior is that of an intruder.
Signature detection
_______ involves the collection of data relating to the behavior of legitimate users over a period of time.
Anomaly detection
A(n) ______ is inserted into a network segment so that the traffic that it is monitoring must pass through the sensor.
inline-sensor
The ______ is the IDS component that examines the data collected by the sensor for signs of unauthorized or undesired activity or for events that might be of interest to the security administrator.
analyzer
On average, ________ of all possible keys must be tried in order to achieve success with a brute-force attack.
half
If the only form of attack that could be made on an encryption algorithm is brute-force, then the way to counter such attacks would be to ________ .
use longer keys
________ is a procedure that allows communicating parties to verify that received or stored messages are authentic.
message authentication
The purpose of a ________ is to produce a ?fingerprint? of a file, message, or other block of data.
hash function
A _________ is created by using a secure hash function to generate a hash value for a message and then encrypting the hash code with a private key.
digital signature
Symmetric encryption is also referred to as secret-key or single-key encryption.
true
The ciphertext-only attack is the easiest to defend against.
true
A brute-force approach involves trying every possible key until an intelligible translation of the ciphertext into plaintext is obtained.
true
AES uses a Feistel structure.
false
Each block of 64 plaintext bits is encoded independently using the same key? is a description of the CBC mode of operation.
false
Timing attacks are only applicable to RSA.
false
Using PKCS (public-key cryptography standard), when RSA encrypts the same message twice, different ciphertexts will be produced.
true
The Diffie-Hellman algorithm depends for its effectiveness on the difficulty of computing discrete logarithms
true
A key exchange protocol is vulnerable to a man-in-the-middle attack if it does not authenticate the participants.
true
Just like RSA can be used for signature as well as encryption, Digital Signature Standard can also be used for encryption
false
In general, public key based encryption is much slower than symmetric key based encryption.
true
________ is the original message or data that is fed into the encryption process as input.
plaintext
Which of the following would allow an attack that to know the (plaintext of) current message must be the same as one previously transmitted because their ciphtertexts are the same?A. CBC B. ECB C. CFB D. OFB
B
________ is a term that refers to the means of delivering a key to two parties that wish to exchange data without allowing others to see the key.
Key distribution technique