CIST 1601: Chapter 7 Quiz Prep

You have downloaded a file from the internet. You generate a hash and check it against the original file's hash to ensure the file has not been changed. Which information security goal is this an example of?

• Authenticity

• Integrity

• Non-repudiation

• Confidentiality

Answer explanation

Integrity ensures that data remains unchanged and has not been tampered with or altered in an unauthorized manner. By comparing the hash values, you can verify the integrity of the file and ensure that it has not been modified since the hash was generated.

Which type(s) of key(s) are used in symmetric cryptography?

• Two unique sets of key pairs

• A single key pair

• A shared key

• A unique key for each participant

Answer explanation

Symmetric cryptography employs the same key for both the encryption of plaintext and the decryption of ciphertext. This shared key must be kept confidential between the communicating parties. This is in contrast to asymmetric cryptography, where two unique sets of key pairs (public and private keys) are used.

Mary wants to send a message to Sam. She wants to digitally sign the message to prove that she sent it. Which key would Mary use to create the digital signature?

• Sam's public key

• Sam's private key

• Her private key

• Her public key

Answer explanation

Digital signatures in asymmetric cryptography involve using the sender's private key to sign the message, and the recipient can verify the signature using the sender's public key. This process ensures the authenticity and integrity of the message.

A receiver wants to verify the integrity of a message received from a sender. A hashing value is contained within the digital signature of the sender. Which of the following must the receiver use to access the hashing value and verify the integrity of the transmission?

• Receiver's private key

• Receiver's public key

• Sender's private key

• Sender's public key

Answer explanation

In digital signatures, the sender uses their private key to sign the message, and the receiver uses the sender's public key to verify the signature and access the hashing value for integrity verification.

Mary wants to send a message to Sam in such a way that only Sam can read it. Which key should be used to encrypt the message?

• Sam's public key

• Sam's private key

• Mary's public key

• Mary's private key

Answer explanation

To ensure that only Sam can read the message, Mary should use Sam's public key to encrypt the message. This is a characteristic of asymmetric cryptography, where the public key is used for encryption, and the corresponding private key, held only by Sam, is used for decryption. Therefore, Mary would encrypt the message with Sam's public key, and only Sam, possessing the corresponding private key, would be able to decrypt and read the message.

Which of the following algorithms are used in asymmetric encryption? (Select two)

• RSA

• Twofish

• AES

• Diffie-Hellman

• Blowfish

Answer explanation

RSA is widely used for both encryption and digital signatures, while Diffie-Hellman is commonly used for key exchange in establishing a secure communication channel. Twofish, AES, and Blowfish are symmetric encryption algorithms.

Above all else, what must be protected to maintain the security and benefit of an asymmetric cryptographic solution, especially if it is widely used for digital certificates?

• Private keys

• Public keys

• Cryptographic algorithm

• Hash values

Answer explanation

Above all else, the private keys must be protected to maintain the security and benefit of an asymmetric cryptographic solution, especially if it is widely used for digital certificates. The security of asymmetric cryptography relies on keeping the private keys secret, as they are used for decryption, digital signature creation, and other sensitive operations. If private keys are compromised, it could lead to unauthorized access, data tampering, and other security risks. Public keys, cryptographic algorithms, and hash values are also important but are generally considered less sensitive and can be openly shared.

When a cryptographic system is used to protect data confidentiality, what actually takes place?

• Encrypted data transmission is prohibited.

• Unauthorized users are prevented from viewing or accessing the resource.

• Data is protected from corruption or change.

• Data is available for access whenever authorized users need it.

Answer explanation

Cryptography ensures that only authorized individuals or systems can access and decrypt the protected data, maintaining its confidentiality and preventing unauthorized access.

Which of the following is the weakest symmetric encryption method?

• DES

• AES

• 3DES

• Twofish

• Blowfish

Answer explanation

DES has a relatively short key length of 56 bits, making it susceptible to brute-force attacks with modern computing power. Both AES (Advanced Encryption Standard) and Twofish are considered more secure than DES. 3DES (Triple DES) is an improvement over DES but is still considered less secure compared to AES.

How many keys are used with symmetric key cryptography?

• 1

• 2

• 4

• 5