Question 1

Rijndael is the block cipher algorithm behind what encryption standard?

Accepted Answer

Rijndael is the encryption algorithm used in AES (Advanced Encryption Standard), which is the current standard encryption algorithm used worldwide. It is composed of three ciphers, AES-128, AES-192, and AES-256. It is highly secure and reliable, and it is widely used in various applications such as e-commerce, banking, and military communications.

Question 2

Asymmetric encryption uses ____ separate keys for each message.

Accepted Answer

Asymmetric encryption uses two separate keys - a public key and a private key - for each message. The public key is widely available and is used by anyone who wants to send a message to the owner of the private key. The private key is kept secret by the owner and is used to decrypt any messages that have been encrypted with the corresponding public key.

Question 3

Historically, attempts to gain unauthorized access to secure communications have used brute force attacks.

Accepted Answer

Brute force attacks, which involve trying every possible combination of passwords or keys until the correct one is found, have been commonly used in the past to gain unauthorized access to secure communications. However, there are now many other methods of attack that can be used, such as social engineering and malware.

Question 4

One of the most popular public key cryptosystems is a proprietary model named ____.

Accepted Answer

The proprietary model mentioned in the question is RSA which stands for Rivest-Shamir-Aldeman. Triple DES and Rijndael are both symmetric key encryption algorithms, not public key cryptosystems. Certificate authority (CA) is not a cryptosystem, but rather a trusted third party that issues digital certificates for validating the identities of websites, individuals, or organizations.

Question 5

According to the computer insurance agency Safeware, Inc.(www.safeware.com), a laptop is stolen every ____.

Accepted Answer

According to Safeware, Inc., a laptop is stolen every 12 seconds.

Question 6

Pure asymmetric key encryption is widely used except in the area of certificates.

Accepted Answer

Certificates typically involve the use of both symmetric and asymmetric key encryption. Asymmetric key encryption is used for the exchange of the public key, while symmetric key encryption is used for encrypting the data being transmitted.

Question 7

The XOR cipher conversion subjects the bitstream to a Boolean XOR function against some other data stream typically a ____ stream "

Accepted Answer

The XOR cipher requires a key stream to XOR with the plaintext or ciphertext to produce the ciphertext or plaintext, respectively. Therefore, the correct choice is D) key.

Question 8

Pretty Good Privacy (PGP) provides security for ____.

Accepted Answer

PGP provides security for e-mail communication. It is a popular encryption tool used for secure email communication, protecting the content of the message from unauthorized access.

Question 9

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

Accepted Answer

A transposition cipher is a type of encryption where the positions of the plain text letters are shifted by a certain amount. Rather than substituting letters for other letters, like in monoalphabetic and polyalphabetic substitution ciphers, a transposition cipher simply rearranges the order of the letters to create the ciphertext. The Vernam cipher, also known as a one-time pad, involves applying a bitwise XOR operation to the plaintext and a random key of the same length to generate the ciphertext.

Question 10

____ was developed by Netscape in 1994 to provide security for online electronic commerce transactions.

Accepted Answer

Secure Sockets Layer (SSL) was developed by Netscape in 1994 to provide security for online electronic commerce transactions. SHTTP and SSH are also security protocols, but they were not specifically developed for e-commerce transactions. Secure Electronic Transactions (SET) is a protocol for securing credit card transactions over the Internet, but it was not developed by Netscape.

Question 11

The reverse of the asymmetric encryption process yields ____.

Accepted Answer

The reverse of the asymmetric encryption process yields digital signatures. Asymmetric encryption involves a public and private key pair, where the public key is used to encrypt data and the private key is used to decrypt it. Digital signatures are a way of verifying the authenticity and integrity of digital information by using the sender’s private key to generate a unique signature that can be verified by anyone with the corresponding public key. This is the reverse process of encryption, so the answer is A.

Question 12

The replacement of one alphabet character with another from more than one alphabets is known as

Accepted Answer

Polyalphabetic substitution involves using more than one alphabet for substitution, unlike monoalphabetic substitution which uses only one. Transposition cipher involves rearranging the positions of the characters rather than substituting them. Caesar cipher is a type of monoalphabetic substitution, where each letter in the plaintext is shifted by a fixed number of positions in the alphabet.

Question 13

____ was developed as an improvement to DES and uses as many as three keys in succession.

Accepted Answer

Triple DES (also known as 3DES) uses three keys in succession to encrypt a message, making it much more secure than DES which only uses one key. Triple DES was developed as an improvement to DES and is still widely used today in many applications. AES, Vernam, and Rijndael are all other encryption algorithms, but they do not directly relate to the development of Triple DES.

Question 14

Text that has been encrypted is called ____.

Accepted Answer

Ciphertext refers to text that has been transformed into a non-readable format using encryption techniques. Plaintext is the original unencrypted text, cryptotext is not a commonly used term, and cryptography refers to the techniques and methods used to secure information.

Question 15

The formula ____ represents the application of encryption (E) to a message (M) to create ciphertext (C)

Accepted Answer

The correct formula for encryption is E(M) = C, meaning the message M is encrypted (E) to create the ciphertext (C).

Question 16

Firewalls have always performed encryption-related functions.

Accepted Answer

Firewalls primarily perform access control functions such as filtering incoming and outgoing traffic based on predefined rules. They may also perform NAT (Network Address Translation) and packet inspection, but not necessarily encryption. Encryption is typically handled by dedicated encryption devices or protocols such as TLS (Transport Layer Security) implemented at the application layer.

Question 17

____ is the process of deciphering the original message from an encrypted message without knowing the algorithms and keys used to perform the encryption.

Accepted Answer

Cryptanalysis is the process of deciphering the original message from an encrypted message without knowing the algorithms and keys used to perform the encryption. Nonrepudiation refers to the ability to prevent denial by one party of the authenticity or origin of a message or contract. Cryptography and cryptology both refer to the practice of secure communication, including encryption and decryption, but do not specifically refer to the process of deciphering an encrypted message without knowledge of the keys and algorithms used.

Question 18

AES has been the federally approved standard for nonclassified data since 2002.

Accepted Answer

The Advanced Encryption Standard (AES) was selected by the National Institute of Standards and Technology (NIST) as the federal government's approved encryption algorithm for nonclassified data in 2002.

Question 19

The process of assuring that parties to a transaction are authentic, so that they cannot later deny having participated is called repudiation.

Accepted Answer

The process of assuring that parties to a transaction are authentic, so that they cannot later deny having participated is called authentication. Repudiation refers to a party denying their involvement in a transaction.

Question 20

MasterCard and VISA developed ____ in 1997.

Accepted Answer

MasterCard and VISA developed Secure Electronic Transactions (SET) in 1997.

Quiz 9: Encryption - The Foundation for the Virtual Private Network