IT Security - Chapter 9

cipher

An algorithm used for cryptographic purposes is known as a ___.

Symmetric (private)

An encryption cipher that uses the same key to encrypt and decrypt is called a ___ key.

Symmetric key algorithms

DES, IDEA, RC4, and WEP are examples of ___.

True

Encryption ciphers fall into two general categories: symmetric (private) key and asymmetric (public) key. True or False?

Online Certificate Status Protocol (OCSP)

What allows a certificate authority (CA) to revoke a compromised digital certificate in real time?

one-way-algorithms (hashing algorithms)

What are encryption algorithms that have no decryption algorithms?

Anonymity; timestamping; revocation; ownership

What are the 4 security measures that benefit everyone?

confidentiality; integrity; authentication; nonrepudiation

What are the four security goals of cryptography?

transposition and substitution

What are the two basic types of ciphers?

Nonrepudiation

What enables you to prevent a party from denying a previous statement or action?

Digital signature

What is a representation of a physical signature stored in a digital format?

encryption

What is the act of scrambling plaintext into ciphertext?

Data Encryption Standard (DES)

What is the most scrutinized cipher in history?

keyspace

What is the number of possible keys to a cipher?

32 to 448 bits

What is the variable key length range for Blowfish?

Factoring large primes

What mathematical problem forms the basis of most modern cryptographic algorithms?

Chosen-plaintext attack

Which cryptographic attack is the best case for the cryptanalyst?

Chosen plaintext

Which cryptographic attack offers cryptanalysts the most information about how an encryption algorithm works?

Certification

Which information security objective allows trusted entities to endorse information?

Symmetric, steam, substitution

Which set of characteristics describes the Caesar cipher accurately?

simple substitution cipher

Which substitution cipher allows any letter to uniquely map to any other letter?

Vigenere Cipher

Which substitution cipher encrypts every letter with its own substitution scheme?

Keyword mixed alphabet cipher

Which substitution cipher users a cipher alphabet that consists of a keyword, minus duplicates, followed by the remaining letters of the alphabet?

Transposition ciphers

Which type of ciphers rearranges characters or bits of data?

Substitution ciphers

Which type of ciphers replaces bits, characters, or blocks of information with other bits, characters or blocks?

Attribute-based encryption (ABE)

Which type of encryption uses descriptive attributes to encrypt and decrypt data?

identity-based encryption (IBE)

Which type of encryption uses the encryptor's identity to derive a key?

Nonrepudiation

___ corroborates the identity of an entity, whether the sender, the sender's computer, some device, or some information.