Network Defense Chapter 12

What type of attack is being performed when the attacker has access to plaintext and ciphertext, and can choose which messages to encrypt? known plaintext chosen-ciphertext chosen-plaintext ciphertext-only

chosen-plaintext

Cryptography is the process of converting plaintext, which is readable text, into unreadable or encrypted text called which if the following? ciphertext cleartext subtext maskedtext

ciphertext

In what type of attack does the attacker have the ciphertext of several messages that were encrypted with the same encryption algorithm, but has no access to the plaintext so he or she must try to calculate the key used to encrypt the data? known plaintext chosen-ciphertext chosen-plaintext ciphertext-only

ciphertext-only

If a security expert decides to study the process of breaking encryption algorithms, they are performing which of the following? cryptography ciphering substitution analysis cryptanalysis

cryptanalysis

What type of system converts between plaintext and ciphertext? cryptokey keyedsystem opensystem cryptosystem

cryptosystem

Which of the following is the process of converting ciphertext back into plaintext? ciphering encryption decoding decryption

decryption

When an attacker has access to a password file, they can run a password-cracking program that uses a dictionary of known words or passwords as an input file. What type of attack is this attacker performing? ciphertext-only brute force dictionary replay

dictionary

Which of the following is a mathematical function or program that works with a key? encryption algorithm generated algorithm key algorithm key

encryption algorithm

Which of the following is a function that takes a variable-length string or message and produces a fixed-length message digest? hashing algorithm RSA algorithm data algorithm VLS algorithm

hashing algorithm

Which of the following is a range of allowable values that is used to generate an encryption key? keyarea key range algorithm area keyspace

keyspace

What type of attack is being conducted when the attacker has messages in both encrypted form and decrypted forms? known plaintext chosen-plaintext chosen-ciphertext ciphertext-only

known plaintext

Which type of symmetric algorithm operates on plaintext one bit at a time? stream ciphers block ciphers open ciphers plain ciphers

stream ciphers

What type of cryptography is demonstrated by reversing the alphabet so A becomes Z, B becomes Y, and so on? alphabet cipher roman cipher complete cipher substitution cipher

substitution cipher

Cryptosystems that have a single key that encrypts and decrypts data are using what type of algorithm? symmetric ciphered single asymmetric

symmetric

Which of the following encryption standards is part of the NSA's suite B cryptographic algorithms and is validated strong enough to protect classified data? IDEA DES Triple DES AES-256

AES-256

What encryption algorithm is efficient requiring few resources, and is based on complex algebra and calculations on curves? DES ECC RSA IDEA

ECC

Which of the following is a scripting language for Windows and Linux that performs repetitive tasks, such as password cracking? EXPECT Pwdump3v2 Hydra (THC) John the Ripper

EXPECT

AES uses a 128-bit key and is used in PGP encryption software. True False

False

Symmetric algorithms use two keys that are mathematically related. True False

False

What application is considered the original password-cracking program and is now used by many government agencies to test for password strength? John the Ripper L0phtcrack Hydra (THC) Pwdump3v2

L0phtcrack

Which function ensures that a sender and receiver cannot deny sending or receiving a specific message? Nonrepudiation Availability Integrity Authentication

Nonrepudiation

Asymmetric algorithms are more scalable than symmetric algorithms. True False

True

ECC is an efficient algorithm requiring few hardware resources, so it's a perfect candidate for wireless devices and cell phones. True False

True

Symmetric algorithms support confidentiality, but not authentication and nonrepudiation. True False

True

A certificate contains a unique serial number and must follow which standard that describes the creating of a certificate? IEEE 802 PKI NIST X.509

X.509

What type of attack is being attempted when an attacker uses a password-cracking program to guess passwords by attempting every possible combination of letters? replay ciphertext-only dictionary brute force

brute force

In what type of attack does the attacker need access to the cryptosystem, and the ciphertext to be decrypted to yield the desired plaintext results? known plaintext ciphertext-only chosen-ciphertext chosen-plaintext

chosen-ciphertext

Which of the following refers to verifying the sender or receiver (or both) is who they claim to be? Authorization Authentication Availability Nonrepudiation

Authentication

What encryption algorithm can be used for both encryption and digital signing, uses a one-way function, and is still widely used in e-commerce? ECC RSA AES DES

RSA

What type of attack is being performed when an attacker intercepts the initial communications between a Web server and a Web browser while forcing a vulnerable server to insecurely renegotiate the encryption being used down to a weaker cipher? Hydra attack TCP/IP attack SSL/TLS downgrade attack Cross Server attack

SSL/TLS downgrade attack