Security Pro Chapter 3

Which of the following would you find on a CPS?

A declaration of the security that the organization is implementing for all certificates

What is a PKI?

A hierarchy of computers for issuing certificates

What type of key or keys are used in symmetric cryptography?

A shared private key

Which of the following best describes high amplification when applied to hashing algorithms?

A small change in the message results in a big change in the hash value.

You want to encrypt data on a removable storage device. Which encryption method would you choose to use the strongest method possible?

AES

Which of the following are true concerning the Advanced Encryption Standard (AES) symmetric block cipher?

AES uses a variable-length block and key length (128-, 192-, or 256 keys), AES uses the Rijndael block cipher

Which of the following conditions does not result in a certificate being added to the certificate revocation list?

Certificate expiration

Your company produces an encryption device that lets you enter text and receive encrypted text in response. An attacker obtains one of these devices and starts inputting random plain text to see the resulting cipher text. What type of attack is this?

Chosen plaintext

When two different messages product the same hash value, what has occurred?

Collision

Which of the following is considered an out-of-band distribution method for private-key encryption?

Copying the key to a USB drive

Hashing algorithms are used to perform what activity?

Create a message digest

Which cryptography system generates encryption keys that could be used with DES, AES, IDEA, RC5, or any other symmetric cryptography solution?

Diffie-Hellman

Which of the following is a direct protection of integrity?

Digital signature

Secure Multi-Purpose Internet Mail Extensions (S/MIME) is used primarily to protect what?

E-mail attachments

Which form of asymmetric cryptography is based upon Diffie-Hellman?

El Gamal

What is the main function of a TPM hardware chip?

Generate and store cryptographic keys

Which of the following is used to verify that a downloaded file has not been altered?

Hash

A birthday attack focuses on what?

Hashing algorithms

Which of the following password attacks adds appendages to known dictionary words?

Hybrid

Which of the following can be used to encrypt Web, e-mail, telnet, file transfer, and SNMP traffic?

IPSec (Internet Protocol Security)

To obtain a digital certificate and participate in a Public Key Infrastructure (PKI), what must be submitted and where should it be submitted?

Identifying data and a certification request to the registration authority (RA)

When an attacker decrypts an encoded message using a different key than was used during encryption, what type of attack has occurred?

Key clustering

Which of the following is not true concerning symmetric key cryptography?

Key management is easy when implemented on a large scale.

You are concerned about the strength of your cryptographic keys, so you implement a system that does the following: The initial key is fed into the input of the bcrypt utility on a Linux workstation. The bcrypt utility produces an enhanced key that is 128 bits long. The resulting enhanced key is much more difficult to crack than the original key. Which kind of encryption mechanism was used in this scenario?

Key stretching

In which type of attack does the attacker have access to both the plain text and the resulting cipher text, but does not have the ability to encrypt the plain text?

Known plaintext

In a cryptographic system, what properties should the initialization vector have?

Large, Unpredictable

Which of the following is the weakest hashing algorithm?

MD5

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?

Mary's private key

When is the best time to apply for a certificate renewal?

Near the end of the certificate's valid lifetime

You have a Web server that will be used for secure transactions for customers who access the Web site over the Internet. The Web server requires a certificate to support SSL. Which method would you use to get a certificate for the server?

Obtain a certificate from a public PKI

How many keys are used with symmetric key cryptography?

One

Which of the following encryption methods combines a random value with the plain text to produce the cipher text?

One-time pad

What technology was developed to help improve the efficiency and reliability of checking the validity status of certificates in large complex environments?

Online Certificate Status Protocol

SHA-1 uses which of the following bit length hashing algorithms?

Only 160-bit

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

Which of the following algorithms are used in symmetric encryption?

Blowfish, AES, 3DES

Which of the following attacks will typically take the longest amount of time to complete?

Brute force attack

What is the primary use of Secure Electronic Transaction (SET)?

Protect credit card information transmissions

Which of the following items are contained in a digital certificate?

Public key, Validity period

Which of the following can be classified as a "stream cipher"?

RC4

Which version of the Rivest Cipher is a block cipher that supports variable bit length keys and variable bit block sizes?

RC5

Which public key encryption system does PGP use for key exchange and digital signatures?

RSA

Which of the following algorithms are used in asymmetric encryption?

RSA, Diffie-Hellman

You have lost the private key that you have used to encrypt files. You need to get a copy of he private key to open some encrypted files. Who should you contact?

Recovery agent

Which of the following is an entity that accepts and validates information contained within a request for a certificate?

Registration authority

Which of the following does not or cannot produce a hash value of 128 bits?

SHA-1

Which of the following is the strongest hashing algorithm?

SHA-1

Which security mechanism can be used to harden or protect e-commerce traffic from Web servers?

SSL

Mary wants to send a message to Sam so that only Sam can read it. Which key would be used to encrypt the message?

Sam's public key

The strength of a cryptosystem is dependent upon which of the following?

Secrecy of the key

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. What must the receiver use to access the hashing value to verify the integrity of the transmission?

Sender's public key

Which of the following technologies is based upon SSL (Secure Sockets Layer)?

TLS (Transport Layer Security)

Match the symmetric key distribution mechanism on the left with the appropriate description on the right. Each distribution mechanism may be used once, more than once, or not at all.

The sender's key is sent to a recipient using a Diffie-Hellman key exchange: In-band distribution The sender's key is copied to a USB drive and handed to the recipient: Out-of-band distribution The sender's key is sent to the recipient using public-key cryptography: In-band distribution The sender's key is burned to a CD and handed to the recipient: Out-of-band distribution

Why are brute force attacks always successful?

They test every possible valid combination

What is the purpose of key escrow?

To provide a means for legal authorities to access confidential data

What type of cipher changes the position of the characters in a plain text message?

Transposition

Which aspect of certificates makes them a reliable and useful mechanism for proving the identity of a person, system, or service on the Internet?

Trusted third-party

How many keys are used with Public Key Cryptography?

Two

How many keys are used with asymmetric or public key cryptography?

Two

Which of the following is not true in regards to S/MIME?

Uses IDEA encrpytion

Which of the following are true of Triple DES (3DES)?

Uses a 168-bit key, Is used in IPSec

Which of the following are characteristics of ECC?

Uses a finite set of values within an algebraic field, Asymmetric encryption

Bob Jones used the RC5 cryptosystem to encrypt a sensitive and confidential file on his notebook. He used 32 bit blocks, a 64 bit key, and he only used the selected key once. He moved the key onto a USB hard drive which was stored in a safety deposit box. Bob's notebook was stolen. Within a few days Bob discovered the contents of his encrypted file on the Internet. What is the primary reason why Bob's file was opened so quickly?

Weak key

HTTPS (Hypertext Transfer Protocol over Secure Socket Layer) can be used to provide security for what type of traffic?

Web

You have just downloaded a file. You create a hash of the file and compare it to the hash posted on the Web site. The two hashes match. What do you know about the file?

Your copy is the same as the copy posted on the website.

Initialization vector

a seed value used in encryption. The seed value and the key are used in an encryption algorithm to generate additional keys or to encrypt data.

Transposition cipher

changes the position of the characters in the plain text message

Steganography

literally meaning "concealed writing," hides data or a message such that only the sender or the recipient suspects that the hidden data exists.

Cipher text

message in a form that makes it unreadable to all but those for whom the message was intended

Cryptanalysis

method of recovering original data that has been encrypted without having access to the key used in the encryption process

Cryptographer

person who develops ways of converting plain text to cipher text

Decryption

procedure used to convert data from cipher text to plain text

Encryption

process of using an algorithm to transform data from plain text to a cipher text in order to protect the confidentiality, integrity, and sometimes the authenticity of the message

Algorithm

process or formula used to convert a message or otherwise hide its meaning.

Plain text

readable message

Substitution Cipher

replaces one set of characters with symbols or another character set

Cryptography

science of converting data into a secret code to hide the meaning of the message during transmission. Provides: confidentiality, integrity, authentication, and non-repudiation

Cryptosystem

the associated items of cryptography that are used as a unit to provide a single means of encryption and decryption

Cryptology

the study of cryptography and cryptanalysis

Quantum crptography

uses a series of photons to encrypt and send a message.

Key

variable in a cipher used to encrypt or decrypt a message. Should be kept secret.

The PGP or Pretty Good Privacy encryption utility relies upon what algorithms?

3DES, IDEA

Which of the following is a form of mathematical attack against the complexity of a cryptosystem's algorithm?

Analytic attack

A PKI is a method for managing which type of encryption?

Asymmetric

What form of cryptography is scalable for use in very large and ever-expanding environments where data is frequently exchanged between different communication partners?

Asymmetric cryptography

Which of the following statements is true when comparing symmetric and asymmetric cryptography?

Asymmetric key cryptography is used to distribute symmetric keys

If two different messages or files produce the same hashing digest, then a collision has occurred. What form of cryptographic attack exploits this condition?

Birthday attack

In what form of key management solution is key recovery possible?

Centralized

Which of the following generates the key pair used in asymmetric cryptography?

CSP

Which of the following encryption mechanisms offers the least security because of weak keys?

DES

Which type of password attack employs a list of pre-defined passwords that it tries against a logon prompt or a local copy of a security accounts database?

Dictionary

Match each public-key cryptography key management mechanism on the left with the corresponding description on the right. Each mechanism may be used once, more than once, or not at all.

Implements the Diffie-Hellman key exchange protocol using elliptic curve cryptography: ECDH Exist only for the lifetime of a specific communication session: Ephemeral keys Uses no deterministic algorithm when generating public keys: Perfect forward secrecy Can be reused by multiple communication sessions: Static keys

Which of the following symmetric block ciphers does not use a variable block length?

International Data Encryption Algorithm (IDEA)

Which of the following communications encryption mechanisms has a specific version for wireless communications?

TLS (Transport Layer Security)

Which form of cryptanalysis focuses on the weaknesses in the supporting computing platform as a means to exploit and defeat encryption?

Statistical attack

What is the cryptography mechanism which hides secret communications within various forms of data?

Steganography

The Enigma machine, a cryptographic tool introduced in 1944 and used in WW2, encrypted messaged by replacing characters for plain text. Which type of cipher does the Enigma machine use?

Substitution

What form of cryptography is not scalable as a stand-alone system for use in very large and ever expanding environments where data is frequently exchanged between different communications partners?

Symmetric cryptography

Which of the following best describes a side-channel attack?

The attack is based on information gained from the physical implementation of a cryptosystem.

If a birthday attack is successful, meaning the attacker discovers a password that generates the same hash as that captured from a user's logon credentials, which of the following is true?

The discovered password will allow the attacker to log on as the user, even if it is not that same as the user's password. A collision was discovered.