Cryptography Quiz

Brian computes the digest of a single sentence of text using a SHA-2 hash function. He then changes a single character of the sentence and computes the hash value again. Which one of the following statements is true about the new hash value?

• The new hash value will be one character different from the old hash value.

• The new hash value will share at least 50 percent of the characters of the old hash value.

• The new hash value will be unchanged.

• The new hash value will be completely different from the old hash value.

Alan believes that an attacker is collecting information about the electricity consumption of a sensitive cryptographic device and using that information to compromise encrypted data. What type of attack does he suspect is taking place?

• Brute-force

• Side-channel

• Known plaintext

• Frequency analysis

If Richard wants to send an encrypted message to Sue using a public key cryptosystem, which key does he use to encrypt the message?

• Richard's public key

• Richard's private key

• Sue's public key

• Sue's private key

If a 2,048-bit plaintext message were encrypted with the ElGamal public key cryptosystem, how long would the resulting ciphertext message be?

• 1,024 bits

• 2,048 bits

• 4,096 bits

• 8,192 bits

Acme Widgets currently uses a 3,072-bit RSA encryption standard companywide. The company plans to convert from RSA to an elliptic curve cryptosystem. If the company wants to maintain the same cryptographic strength, what ECC key length should it use?

• 256 bits

• 512 bits

• 1,024 bits

• 2,048 bits

John wants to produce a message digest of a 2,048-byte message he plans to send to Mary. If he uses the SHA-2 hashing algorithm, what is a possible size for the message digest generated?

• 160 bits

• 512 bits

• 1,024 bits

• 2,048 bits

After conducting a survey of encryption technologies used in her organization, Melissa suspects that some may be out of date and pose security risks. Which one of the following technologies is considered flawed and should no longer be used?

• SHA-3

• TLS 1.3

• IPSec

• SSL 3.0

You are developing an application that compares passwords to those stored in a Unix password file. The hash values you compute are not correctly matching those in the file. What might have been added to the stored password hashes?

• Salt

• Double hash

• Added encryption

• One-time pad

Richard received an encrypted message sent to him from Sue. Sue encrypted the message using the RSA encryption algorithm. Which key should Richard use to decrypt the message?

• Richard's public key

• Richard's private key

• Sue's public key

• Sue's private key

Richard wants to digitally sign a message he's sending to Sue so that Sue can be sure the message came from him without modification while in transit. Which key should he use to encrypt the message digest?

• Richard's public key

• Richard's private key

• Sue's public key

• Sue's private key