Quiz 9 Information Security Fundamentals

Bob received a message from Alice that contains a digital signature. What cryptographic key does Bob use to verify the digital signature?

*Alice's public key* Alice's private key Bob's public key Bob's private key

Which cryptographic attack offers cryptanalysts the most information about how an encryption algorithm works?

*Chosen plaintext* Ciphertext only Known plaintext Chosen ciphertext

Digital signatures require asymmetric key cryptography.

*True* False

Which approach to cryptography provides the strongest theoretical protection?

Quantum cryptography Asymmetric cryptography < wrong Elliptic curve cryptography Classic cryptography

Alice and Bob would like to communicate with each other using a session key but they do not already have a shared secret key. Which algorithm can they use to exchange a secret key?

Rivest, Shamir, Adelman (RSA) Message digest algorithm (MD5) Blowfish *Diffie-Hellman*

Which information security objective allows trusted entities to endorse information?

Validation <wrong Authorization Certification Witnessing

A substitution cipher replaces bits, characters, or blocks of information with other bits, characters, or blocks.

*True* False

In a chosen-ciphertext attack, cryptanalysts submit data coded with the same cipher and key they are trying to break to the decryption device to see either the plaintext output or the effect the decrypted message has on some system.

*True* False

Integrity-checking tools use cryptographic methods to make sure nothing and no one has modified the software.

*True* False

The Diffie-Hellman (DHE) algorithm is the basis for several common key exchange protocols, including Diffie-Hellman in Ephemeral mode (DHE) and Elliptic Curve DHE (ECDHE).

*True* False

Alice would like to send a message to Bob using a digital signature. What cryptographic key does Alice use to create the digital signature?

Alice's public key *Alice's private key* Bob's public key Bob's private key

Which set of characteristics describes the Caesar cipher accurately?

Asymmetric, block, substitution < wrong Asymmetric, stream, transposition Symmetric, stream, substitution Symmetric, block, transposition

What is NOT an effective key distribution method for plaintext encryption keys?

Paper *Unencrypted email* CD Smart card

What is the only unbreakable cipher when it is used properly?

Rivest-Shamir-Adelman (RSA) *Vernam* Elliptic Curve Diffie-Hellman in Ephemeral mode (ECDHE) Blowfish

A private key cipher is also called an asymmetric key cipher.

True *False*

Cryptographic key distribution is typically done by phone.

True *False*

The term certificate authority (CA) refers to a trusted repository of all public keys.

True *False*

You must always use the same algorithm to encrypt information and decrypt the same information.

True *False*

In a known-plaintext attack (KPA), the cryptanalyst has access only to a segment of encrypted data, and has no choice as to what that data might be.

True *False* it's *Ciphertext-only attack (COA)*

What is NOT a symmetric encryption algorithm?

*Rivest-Shamir-Adelman (RSA)* Data Encryption Standard (DES) International Data Encryption Algorithm (IDEA) Carlisle Adams Stafford Tavares (CAST

A keyword mixed alphabet cipher uses a cipher alphabet that consists of a keyword, minus duplicates, followed by the remaining letters of the alphabet.

*True* False

What mathematical problem forms the basis of most modern cryptographic algorithms?

Factoring large primes Traveling salesman problem Quantum mechanics < wrong Birthday problem

A salt value is a set of random characters you can combine with an actual input key to create the encryption key.

*True* False

What standard is NOT secure and should never be used on modern wireless networks?

*Wired Equivalent Privacy (WEP)* Wi-Fi Protected Access (WPA) Wi-Fi Protected Access version 2 (WPA2) 802.11ac

What is NOT a valid encryption key length for use with the Blowfish algorithm?

32 bits 64 bits 256 bits *512 bits*

Which of the following allows a certificate authority (CA) to revoke a compromised digital certificate in real time?

Certificate revocation list (CRL) < wrong International Data Encryption Algorithm (IDEA) < wrong Transport Layer Security (TLS) Online Certificate Status Protocol (OCSP)

Gary is sending a message to Patricia. He wants to ensure that nobody tampers with the message while it is in transit. What goal of cryptography is Gary attempting to achieve?

Confidentiality *Integrity* Authentication Nonrepudiation

When Patricia receives a message from Gary, she wants to be able to demonstrate to Sue that the message actually came from Gary. What goal of cryptography is Patricia attempting to achieve?

Confidentiality Integrity Authentication < wrong Nonrepudiation

What type of function generates the unique value that corresponds to the contents of a message and is used to create a digital signature?

Elliptic curve Decryption Encryption *Hash*

Betty receives a cipher text message from her colleague Tim. What type of function does Betty need to use to read the plaintext message?

Encryption Hashing *Decryption* Validation

Product cipher is an encryption algorithm that has no corresponding decryption algorithm.

True *False* it's *One-way algorithm*

The financial industry created the ANSI X9.17 standard to define key management procedures.

*True* False