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What Is The Standard For Pki Certificates

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QUESTION 1

Digital signatures are used to do which of the following?

ANSWER

Provide authentication and nonrepudiation

QUESTION 2

What is the standard for PKI certificates?

ANSWER

X.509

QUESTION 3

List the three MIT professors who developed the RSA algorithm.

ANSWER

Rivest, Shamir, and Adleman

QUESTION 4

A hash value is a fixed-length string used to verify message integrity. True or False?

ANSWER

True

QUESTION 5

OpenPGP is focused on protecting which of the following?

ANSWER

E-mail messages

QUESTION 6

Intruders can perform which kind of attack if they have possession of a company's password hash file?

ANSWER

Dictionary

QUESTION 7

Intercepting messages destined for another computer and sending back messages while pretending to be the other computer is an example of what type of attack?

ANSWER

Man-in-the-middle

QUESTION 8

A certification authority (CA) issues private keys to recipients. True or False?

ANSWER

False

QUESTION 9

Write the equation to calculate how many keys are needed to have 20 people communicate with symmetric keys.

ANSWER

n(n - 1) / 2 = number of symmetric keys, or 20(20 - 1) / 2 = 190 keys

QUESTION 10

Why did the NSA decide to drop support for DES?

ANSWER

The processing power of computers had increased.

QUESTION 11

Symmetric algorithms can be block ciphers or stream ciphers. True or False?

ANSWER

True

QUESTION 12

Which of the following describes a chosen-plaintext attack?

ANSWER

The attacker has plaintext, can choose what part of the text gets encrypted, and has access to the ciphertext.

QUESTION 13

Two different messages producing the same hash value results in which of the following?

ANSWER

Collision

QUESTION 14

Which of the following is a program for extracting Windows password hash values?

ANSWER

Fgdump

QUESTION 15

Advanced Encryption Standard (AES) replaced DES with which algorithm?

ANSWER

Rijndael

QUESTION 16

What cryptographic devices were used during World War II?

ANSWER

a. Enigma machine c. Purple Machine d. Bombe

QUESTION 17

Asymmetric cryptography systems are which of the following?

ANSWER

Slower than symmetric cryptography systems

QUESTION 18

Diffie-Hellman is used to encrypt e-mail messages. True or False?

ANSWER

False

QUESTION 19

Hiding data in a photograph is an example of which of the following?

ANSWER

Steganography

QUESTION 20

Which of the following is an asymmetric algorithm?

ANSWER

RSA

QUESTION 21

Ciphertext is data that has been

ANSWER

encrypted

QUESTION 22

plaintext is also called

ANSWER

cleartext

QUESTION 23

data that can be read by anyone

ANSWER

also called cleartext

QUESTION 24

Symmetric cryptography uses _______ to encrypt and decrypt data.

ANSWER

one key

QUESTION 25

The two main types of symmetric algorithms are

ANSWER

block ciphers and stream ciphers.

QUESTION 26

Block ciphers, such as AES, operate on _______________of data

ANSWER

fixed-length chunks

QUESTION 27

stream ciphers, such as RC4, operate on _________ of data at a time.

ANSWER

one bit

QUESTION 28

Asymmetric cryptography is also called?

ANSWER

public key cryptography

QUESTION 29

Asymmetric cryptography, also called public key cryptography uses how many keys?

ANSWER

2

QUESTION 30

What are the Asymmetric cryptography keys?

ANSWER

one key to encrypt and another to decrypt data

QUESTION 31

In public key cryptography, a public key can be downloaded from ________ and is mathematically related to a private key known only to the owner.

ANSWER

a Web site

QUESTION 32

A private key is

ANSWER

never shared

QUESTION 33

RSA uses only a one-way function to generate a _____

ANSWER

key

QUESTION 34

RSA uses only a ___________to generate a key

ANSWER

one-way function

QUESTION 35

Diffie-Hellman, ECC, and EIGamal use ___________, __________, and __________to secure data.

ANSWER

encryption, key distribution, and digital signatures

QUESTION 36

Digital Signature Standard (DSS) ensures that ______________ can be verified.

ANSWER

digital signatures

QUESTION 37

To create a _______________, the hash value must be encrypted with the sender's private key.

ANSWER

digital signature

QUESTION 38

To create a digital signature, the ___________must be encrypted with the sender's private key.

ANSWER

hash value

QUESTION 39

To create a digital signature, the hash value must be encrypted with the sender's ______________.

ANSWER

private key

QUESTION 40

To create a digital signature, the hash value must be ___________ with the sender's private key.

ANSWER

encrypted

QUESTION 41

A free public key encryption standard based on the PGP e-mail encryption program.

ANSWER

OpenPGP

QUESTION 42

Public key encryption standard, included in Microsoft Outlook, for encrypting e-mail.

ANSWER

S/MIME

QUESTION 43

Used to verify data integrity

ANSWER

Hashing algorithms

QUESTION 44

A structure made up of several components for encrypting data.

ANSWER

PKI

QUESTION 45

PKI includes __________, _________, and _________.

ANSWER

protocols, programs, and security policies

QUESTION 46

PKI uses ______________to protect data transmitted over the Internet.

ANSWER

public key cryptography

QUESTION 47

A file issued by a certification authority (CA) that binds a public key to information about its owner.

ANSWER

digital certificate

QUESTION 48

An active attack on a cryptosystem attempts to determine the

ANSWER

secret key used to encrypt plaintext.

QUESTION 49

A passive attack on a cryptosystem uses

ANSWER

sniffing and scanning tools

QUESTION 50

Birthday attacks, brute-force attacks, mathematical attacks, man-in-the-middle attacks, replay attacks, and dictionary attacks are examples of

ANSWER

active attacks

QUESTION 51

Wireshark, Tcpdump, Nmap, Unicornscan, and others that don't affect the algorithm (key), message, or any parts of the encryption system are examples of

ANSWER

passive attacks

QUESTION 52

Attacks used to find the same hash value for two different inputs and reveal mathematical weaknesses in a hashing algorithm.

ANSWER

birthday attacks

QUESTION 53

A symmetric algorithm that encrypts data in blocks of bits. These blocks are used as input to mathematical functions that perform substitution and transposition of the bits, making it difficult for someone to reverse-engineer the mathematical functions that were used.

ANSWER

block cipher

QUESTION 54

A block cipher that operates on 64-bit blocks of plaintext, but its key length can be as large as 448 bits.

ANSWER

Blowfish

QUESTION 55

An attack in which the attacker uses software that attempts every possible combination of characters to guess passwords.

ANSWER

brute-force attack

QUESTION 56

A digital document that verifies whether two parties exchanging data over the Internet are really who they claim to be. Each certificate has a unique serial number and must follow the X.509 standard.

ANSWER

certificate

QUESTION 57

A third party, such as VeriSign, that vouches for a company's authenticity and issues a certificate binding a public key to a recipient's private key.

ANSWER

certification authority (CA)

QUESTION 58

A key that maps each letter or number to a different letter or number.

ANSWER

cipher

QUESTION 59

Plaintext (readable text) that has been encrypted.

ANSWER

ciphertext

QUESTION 60

A field of study devoted to breaking encryption algorithms.

ANSWER

cryptanalysis

QUESTION 61

Any data not moving through a network or being used by the OS; usually refers to data on storage media.

ANSWER

data at rest

QUESTION 62

The encryption algorithm used in the DES standard; a symmetric algorithm that uses 56 bits for encryption.

ANSWER

Data Encryption Algorithm (DEA)

QUESTION 63

A NIST standard for protecting sensitive but unclassified data; it was later replaced because the increased processing power of computers made it possible to break DES encryption.

ANSWER

Data Encryption Standard (DES)

QUESTION 64

An attack in which the attacker runs a password-cracking program that uses a dictionary of known words or passwords as an input file against the attacked system's password file.

ANSWER

dictionary attack

QUESTION 65

A method of signing messages by using asymmetric encryption that ensures authentication and nonrepudiation.

ANSWER

digital signature

QUESTION 66

A mathematical formula or method for converting plaintext into ciphertext.

ANSWER

encryption algorithm

QUESTION 67

A function that takes a variable-length string or message and produces a fixed-length hash value, also called a message digest.

ANSWER

hashing algorithm

QUESTION 68

A block cipher that operates on 64-bit blocks of plaintext and uses a 128-bit key; used in PGP encryption software.

ANSWER

International Data Encryption Algorithm (IDEA)

QUESTION 69

A sequence of random bits used in an encryption algorithm to transform plaintext into ciphertext, or vice versa.

ANSWER

key

QUESTION 70

The range of all possible key values contained in an encryption algorithm.

ANSWER

keyspace

QUESTION 71

An attack in which attackers place themselves between the victim computer and another host computer, and then intercept messages sent from the victim to the host and pretend to be the host computer.

ANSWER

man-in-the-middle attack

QUESTION 72

An attack in which properties of the encryption algorithm are attacked by using mathematical computations. Categories of this attack include ciphertextonly attack, known plaintext attack, chosen-plaintext attack, chosen-ciphertext attack, and side-channel attack.

ANSWER

mathematical attack

QUESTION 73

The fixed-length value that a hashing algorithm produces; used to verify that data or messages haven't been changed.

ANSWER

message digest

QUESTION 74

A 128-bit cryptographic hash function; still used, even though its weaknesses make finding collisions practical with only moderate computing power. Most useful for file integrity checking.

ANSWER

Message Digest 5 (MD5)

QUESTION 75

The process of ensuring that the sender and receiver can't deny sending or receiving the message; this function is available in asymmetric algorithms but not symmetric algorithms.

ANSWER

nonrepudiation

QUESTION 76

The Internet public key encryption standard for PGP messages; can use AES, IDEA, RSA, DSA, and SHA algorithms for encrypting, authenticating, verifying message integrity, and managing keys. The most common free version is GNU Privacy Guard (GnuPG or GPG).

ANSWER

OpenPGP

QUESTION 77

Readable text that hasn't been encrypted; also called cleartext.

ANSWER

plaintext

QUESTION 78

A free e-mail encryption program that allows typical users to encrypt e-mails.

ANSWER

Pretty Good Privacy (PGP)

QUESTION 79

In a key pair, the secret key used in an asymmetric algorithm that's known only by the key owner and is never shared. Even if the public key that encrypted a message is known, the owner's private key can't be determined.

ANSWER

private key

QUESTION 80

In a key pair, the key that can be known by the public; it works with a private key in asymmetric key cryptography, which is also known as public key cryptography.

ANSWER

public key

QUESTION 81

Also known as asymmetric key cryptography, an asymmetric algorithm that uses two mathematically related keys.

ANSWER

public key cryptography

QUESTION 82

A structure consisting of programs, protocols, and security policies.

ANSWER

public key infrastructure (PKI)

QUESTION 83

A lookup table of password hash values that enables certain programs to crack passwords much faster than with brute-force methods.

ANSWER

rainbow table

QUESTION 84

A stream cipher created by Ronald L. Rivest that's used in WEP wireless encryption.

ANSWER

RC4

QUESTION 85

A block cipher created by Ronald L. Rivest that can operate on different block sizes: 32, 64, and 128 bits. The key size can reach 2048 bits.

ANSWER

RC5

QUESTION 86

An attack in which the attacker captures data and attempts to resubmit the data so that a device, such as a workstation or router, thinks a legitimate connection is in effect.

ANSWER

replay attack

QUESTION 87

The NIST standard hashing algorithm that's much stronger than MD5 but has demonstrated weaknesses. For sensitive applications, NIST recommends not using SHA-1, and federal agencies are replacing it with longer digest versions, collectively called SHA-2.

ANSWER

Secure Hash Algorithm (SHA)

QUESTION 88

A public key encryption standard for encrypting and digitally signing e-mail. It can also encrypt e-mails containing attachments and use PKI certificates for authentication.

ANSWER

Secure Multipurpose Internet Mail Extension (S/MIME)

QUESTION 89

The method of hiding data in plain view in pictures, graphics, or text.

ANSWER

steganography

QUESTION 90

A symmetric algorithm that operates on plaintext one bit at a time.

ANSWER

stream cipher

QUESTION 91

An encryption algorithm that uses only one key to encrypt and decrypt data. The recipient of a message encrypted with a key must have a copy of the same key to decrypt the message.

ANSWER

symmetric algorithm

QUESTION 92

A cipher that maps each letter of the alphabet to a different letter. The Book of Jeremiah was written by using a substitution cipher called Atbash.

ANSWER

substitution cipher

QUESTION 93

A standard developed to address the vulnerabilities of DES; it improved security, but encrypting and decrypting data take longer.

ANSWER

Triple Data Encryption Standard (3DES)

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