Chapter 12: Cryptography

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?

AES-256

Which of the following refers to verifying the sender or receiver (or both) is who they claim to be? Group of answer choices

Authentication

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

ECC

Which of the following is a scripting language for Windows and Linux that performs repetitive tasks, such as password cracking?

EXPECT

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

False

Symmetric algorithms use two keys that are mathematically related.

False

What application is considered the original password-cracking program and is now used by many government agencies to test for password strength?

L0phtcrack

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

Nonrepudiation

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?

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?

SSL/TLS downgrade attack

Asymmetric algorithms are more scalable than symmetric algorithms.

True

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

True

Symmetric algorithms support confidentiality, but not authentication and nonrepudiation.

True

A certificate contains a unique serial number and must follow which standard that describes the creating of a certificate?

X.509

Uses two keys: one to encrypt data and one to decrypt data Encryption algorithm used for the Data Encryption Standard Uses a single key to encrypt and decrypt data A digital document that verifies the two parties exchanging data over the Internet are really who they claim to be Used for verification, takes a variable-length input and converts it to a fixed-length output string Used to find the same hash value for two different inputs and reveal any mathematical weaknesses in a hashing algorithm Operate on plaintext one bit at a time A structure consisting of programs, protocols, and security policies for encrypting data and uses public key cryptography to protect data transmitted over the Internet A sequence of random bits generated from a range of allowable values The use of random data alongside plaintext as an input to a hashing function so that the output is unique

asymmetric algorithm DEA symmetric algorithm certificate hashing algorithm birthday attacks stream cipher PKI key salt

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?

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?

chosen-ciphertext

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

chosen-plaintext

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

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? Group of answer choices

ciphertext-only

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

cryptanalysis

What type of system converts between plaintext and ciphertext?

cryptosystem

Which of the following is the process of converting ciphertext back into plaintext?

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?

dictionary

Which of the following is a mathematical function or program that works with a 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

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

keyspace

What type of attack is being conducted when the attacker has messages in both encrypted form and decrypted forms?

known plaintext

Which type of symmetric algorithm operates on plaintext one bit at a time?

stream ciphers

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

substitution cipher

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

symmetric