Question 1

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

Accepted Answer

DES uses a 64-bit block size.

Question 2

More advanced substitution ciphers use two or more alphabets, and are referred to as __________ substitutions.

Accepted Answer

Multialphabetic substitutions would only use two alphabets, while polyalphabetic substitutions involve the use of multiple alphabets. Monoalphabetic refers to a cipher that only uses one alphabet. Polynomic is not a term commonly used in cryptography.

Question 3

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

Accepted Answer

CRL stands for Certificate Revocation List, which is a list containing the serial numbers of all the certificates that have been revoked by the CA. The CA periodically distributes the CRL to all users so that they can check if any of the certificates they are relying on have been revoked. This helps to maintain the integrity and security of the PKI system.

B) RA stands for Registration Authority, which is responsible for verifying the identity of users and issuing digital certificates. RA does not distribute the CRL.

C) MAC stands for Message Authentication Code, which is used for ensuring the authenticity and integrity of messages. MAC does not relate to the distribution of CRL.

D) RDL is not a standard term used in PKI.

Question 4

A method of encryption that requires the same secret key to encipher and decipher the message is known as __________ encryption.

Accepted Answer

Symmetric encryption uses the same secret key for both encryption and decryption of data. Asymmetric encryption (choice A) uses two different keys, one for encryption and one for decryption. Public key encryption (choice C) is a type of asymmetric encryption that uses a publicly available key for encryption and a private key for decryption. Private key encryption (choice D) is a vague term and is not a commonly used form of encryption.

Question 5

The __________ is responsible for the fragmentation, compression, encryption, and attachment of an SSL header to the cleartext prior to transmission.

Accepted Answer

The SSL Record Protocol is responsible for fragmenting (if needed), compressing (if instructed), encrypting, and attaching an SSL header to the cleartext prior to transmission. Standard HTTP, SFTP, and S-HTTP are not directly involved in this process.

Question 6

__________ functions are mathematical algorithms that generate a message summary or digest to confirm the identity of a specific message and to confirm that there have not been any changes to the content.

Accepted Answer

Hash functions generate a fixed-length message digest or summary from a message of any size, and it is primarily used to ensure the integrity and authenticity of the message. It creates a unique digital fingerprint, making it particularly useful in verifying that a message has not been tampered with or altered in transit. Maps are data structures used to store key-value pairs, whereas keys are used to unlock the content of encrypted messages. While encryption is used to scramble and hide the content of a message, hash functions generate a summary or hash of the message content.

Question 7

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

Accepted Answer

PGP (Pretty Good Privacy) was developed by Phil Zimmermann and uses the IDEA cipher for message encoding. PEM and S/MIME are also encryption and authentication protocols, but they use different ciphers. SSL (Secure Sockets Layer) is a security protocol used for secure communication over the internet, but it does not use PGP or IDEA cipher.

Question 8

__________ 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.

Accepted Answer

The correct answer is AES (Advanced Encryption Standard), which is the current federal information processing standard used by federal agencies to protect their information. DES and 2DES are outdated encryption standards that have been replaced by AES. 3DES is still used in some applications, but it is less secure and less efficient than AES.

Question 9

Digital signatures should be created using processes and products that are based on the __________.

Accepted Answer

Digital signatures should be created using processes and products that are based on the Digital Signature Standard (DSS), which is a federal standard for digital signatures.

Question 10

An X.509 v3 certificate binds a ___________, which uniquely identifies a certificate entity, to a user's public key.

Accepted Answer

An X.509 v3 certificate binds a distinguished name, which uniquely identifies a certificate entity, to a user's public key. The distinguished name (DN) typically includes information about the entity such as its common name, organizational unit, organization, and country.

Question 11

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

Accepted Answer

SHA-1 produces a 160-bit message digest, which is commonly used as input to digital signature algorithms. Options A and B are incorrect because they are smaller than 160 bits, while Option D is incorrect because SHA-1 produces a 160-bit message digest and not a 256-bit message digest.

Question 12

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

Accepted Answer

The AH (Authentication Header) protocol provides system-to-system authentication and data integrity verification, but does not provide secrecy for the content of a network communication. The ESP (Encapsulating Security Payload) protocol provides both authentication and encryption of network communication content. The HA (Home Agent) protocol is used in the Mobile IPv6 (Internet Protocol version 6) for routing packets to a mobile node's home network. The SEP (Secure Electronic Protocol) is a protocol used in the banking industry for secure online transactions.

Question 13

At the World Championships in Athletics in Helsinki in August 2005, a virus called Cabir infected dozens of __________, the first time this occurred in a public setting.

Accepted Answer

The virus Cabir infected dozens of Bluetooth mobile phones at the World Championships in Athletics in Helsinki in August 2005.

Question 14

_________ is a hybrid cryptosystem that combines some of the best available cryptographic algorithms and has become the open-source de facto standard for encryption and authentication of e-mail and file storage applications.

Accepted Answer

PGP (Pretty Good Privacy) is a hybrid cryptosystem that combines symmetric-key encryption and public-key cryptography. It is widely used for secure e-mail communication and file storage applications, and is considered the open-source de facto standard for encryption and authentication. DES and AES are symmetric-key encryption algorithms, while AH and ESP are protocols used for IPsec (Internet Protocol Security).

Question 15

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

Accepted Answer

Digital signatures use public key cryptography to encrypt a hash of the message to prove authenticity and provide non-repudiation. MACs (Message Authentication Codes) use symmetric key cryptography to generate a tag that verifies message integrity but do not provide non-repudiation. Message certificates are used to verify the identity of the sender and do not provide message encryption. Message digests are a hash of the message to ensure data integrity but do not provide encryption or authentication.

Question 16

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

Accepted Answer

PKI (Public Key Infrastructure) is an integrated system of software, encryption methodologies, protocols, legal agreements, and third-party services that enables users to communicate securely. It primarily involves the use of public and private keys to encrypt and decrypt data, and the verification of the identity of parties involved in the communication using digital certificates. MAC (Message Authentication Code), DES (Data Encryption Standard), and AES (Advanced Encryption Standard) are encryption techniques and not a complete system for secure communication.

Question 17

The __________ algorithm, developed in 1977, was the first public-key encryption algorithm published for commercial use.

Accepted Answer

The RSA algorithm, developed by Ron Rivest, Adi Shamir, and Leonard Adleman in 1977, was the first public-key encryption algorithm published for commercial use. DES (Data Encryption Standard) was a symmetric-key algorithm developed earlier in the 1970s. MAC (Message Authentication Code) is a way to verify the integrity and authenticity of a message. AES (Advanced Encryption Standard) was developed in the late 1990s to replace DES as a symmetric-key algorithm.

Question 18

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

Accepted Answer

IPSec is a protocol that can be used for secure communications across any IP-based network such as LANs, WANs, and the Internet. It provides encrypted and authenticated security services to protect data transmitted over the network. PEM is a digital certificate format, SET is a protocol used for secure online credit card transactions, and SSH is a protocol used for secure remote access to network devices.

Question 19

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.

Accepted Answer

A rainbow table is a database of precomputed hashes from sequentially calculated passwords. An attacker can simply look up a hashed password and read out the text version from a rainbow table. The other choices (A, B, and D) are unrelated to password cracking techniques.

Question 20

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

Accepted Answer

The given description is of a MAC (Message Authentication Code), which uses a symmetric key to generate a unique message digest that only specific recipients with the same key can access. Signatures are used for authentication using public-key cryptography, fingerprints are a specific type of hash function used for biometric identification, and digest is a general term for a hash function output.

Quiz 8: Cryptography