Chapter 8 Cryptography

_ is the amount of effort (usually in hours) required to perform cryptanalysis to decode an encrypted message when the key or algorithm (or both) are unknown.

Work factor

A digital _ is an electronic document or container file that contains a key value and identifying information about the entity that controls the key.

certificate

A(n) _ or cryptosystem is an encryption method or process encompassing the algorithm, key(s) or cryptovariable(s), and procedures used to perform encryption and decryption.

cipher

The process of obtaining the plaintext message from a ciphertext message without knowing the keys used to perform the encryption is called _ .

cryptanalysis

The process of obtaining the plaintext message from a ciphertext message without knowing the keys used to perform the encryption is called _.

cryptanalysis

_ is the process of making and using codes to secure the transmission of information.

cryptography

To _ means to encrypt, encode, or convert plaintext into the equivalent ciphertext.

encipher

Hashing functions do not require the use of keys, but it is possible to attack a _ code to allow only specified recipients to access the message digest.

message authentication

The more common name for asymmetric encryption is _ -key encryption.

public

Using a database of precomputed hashes from sequentially calculated passwords called a(n) _, an attacker can simply look up a hashed password and read out the text version.

rainbow table

Using a database of precomputed hashes from sequentially calculated passwords called a(n) _. An attacker can simply look up a hashed password and read out the text version.

rainbow table

Digital _ are encrypted messages that can be mathematically proven to be authentic.

signatures

The process of hiding messages within the digital encoding of a picture or graphic is called _.

steganography

In IPSec _ mode, only the IP data is encrypted, not the IP headers.

transport

The _ cipher simply rearranges the values within a block to create the ciphertext.

transposition or permutation

PKI systems are absed on public-key cryptosystems and include digital certificates and certificate authorities.

True

Popular cryptosystems use a hybrid combination of symmetric and asymmetric algorithms.

True

Secure Electronic Transactions was developed by MasterCard and Visa in 1997 to protect against electronic payment fraud.

True

Secure Multipurpose Internet Mail Extensions builds on the encoding format of the MIME protocol and uses digital signatures based on public-key cryptosystems to secure e-mail.

True

The Digital Signature Standard established by NIST is used for electronic document authentication by federal information systems. It is based on a variant of the ElGamal algorithm.

True

When asymmetric cryptographic process uses the sender's private key to encrypt a message, the sender's public key must be used to decrypt the message.

True

You cannot combine the XOR operation with a block cipher operation.

False

_ is a protocol that can be used to secure communications across any IOP-cased network such as LANs, WANs, and the Internet.

IPSec

_ is a protocol that can be used to secure communications across any IP-based network such as LANs, WANs, and the Internet.

IPSec

Bluetooth is a de facto industry standard for short-range wireless communications between devices.

True

Ciphertext or a cryptogram is an encoded message, or a message that has been successfully encrypted.

True

In 1917, Gilbert S. Vernam, an AT&T employee, invented a polyalphabetic cipher machine that used a non-repeating random key.

True

In PKI, the CA periodically distributes a(n) _ to all users that identifies all revoked certificates.

CRL

SSL builds on the encoding format of the Multipurpose Internet Mail Extensions protocol and uses digital signatures based on public-key cryptosystems to secure e-mail.

False

The S-HTTP security solution provides six services: authentication by digital signatures, message encryption, compression, e-mail compatibility, segmentation, and key management.

False

The number of horizontal and vertical pixels captured and recorded is known as the image's contrast.

False

To perform the Caesar cipher encryption operation, the pad values are added to numeric values that represent the plaintext that needs to be encrypted.

False

To perform the Caesar cipher encryption operation, the pad values area added to numeric values that represent the plaintext that needs to be encrypted.

False

UltraViolet wireless (UVW) is a de facto industry standard for short-range wireless communications between devices.

False

SHA-1 produces a(n) _ -bit message digest, which can then be used as an input to a digital signature algorithm.

160

DES uses a(n) _ -bit block size.

64

_ is the current federal information processing standard that specifies a cryptographic algorithm used within the U.S. government to protect information in federal agencies that are not a part of the national defense infrastructure.

AES

The _ protocol provides system-to-system authentication and data integrity verification, but does not provide secrecy for the content of a network communication.

AH

The successor to 3DES is the _ Encryption Standard.

Advanced

_ are encrypted message components that can be mathematically proven to be authentic.

Digital signatures

A cryptovariable is a value representing the application of a hash algorithm on a message.

False

A multipart authentication code(MAC) is a key-dependent, one-way hash function that allows only specific recipients (symmetric key holders) to access the message digest.

False

Adopted by NIST in 1976 as a federal standard, DES uses a 64-bit block size and key

False

Asymmetric encryption systems use a single key to both encrypt and decrypt a message.

False

Encryption methodologies that require the same secret key to encipher and decipher the message are using what is called public-key encryption.

False

Hashing functions require the use of keys.

False

In 1953, Giovan Batista Bellaso introduced the idea of the passphrase (password) as a key for encryption.

False

In transport mode the entire IP packet is encrypted and is then placed as the content portion of another IP packet.

False

_ was developed by Phil Zimmerman and uses the IDEA cipher for message encoding.

PGP

_ was developed by Phil Zimmermann and uses the IDEA cipher for message encoding.

PGP

Originally released as freeware, _ is a hybrid cryptosystem that combines some of the best available cryptographic algorithms as an open-source de facto standard for encryption and authentication of e-mail and file storage.

PGP or Pretty Good Privacy

_ is an integrated system of software, encryption methodologies, protocols, legal agreements, and third-party services that enables users to communicate securely.

PKI

A(n) distinguished name uniquely identifies a certificate entity to a user's public key.

True