Security chapter 3

Diffie-Hellman Ephemeral (DHE)

A Diffie-Hellman key exchange that uses different keys

Pseudorandom Number Generator (PRNG)

An algorithm for creating a sequence of numbers whose properties approximate those of a random number.

Elliptic Curve Cryptography (ECC)

An algorithm that uses elliptic curves instead of prime numbers to compute keys.

Private Key

An asymmetric encryption key that does have to be protected.

Public Key

An asymmetric encryption key that does not have to be protected

A. Collisions should be rare.

Which of these is NOT a characteristic of a secure hash algorithm? A. Collisions should be rare. B. A message cannot be produced from a predefined hash. C. The results of a hash function should not be reversed. D. The hash should always be the same fixed size.

C. Advanced Encryption Standard

Which of these is the strongest symmetric cryptographic algorithm? A. Data Encryption Standard B. Triple Data Encryption Standard C. Advanced Encryption Standard D. RC 1

Low Latency

A small amount of time that occurs between when a byte is input into a crypographic algorithm and the time the output is obtained.

Birthday Attack

A statistical phenomenon that makes finding collisions easier.

Downgrade Attack

An attack in which the system is forced to abandon the current higher security mode of operation and fall back to implementing an older and less secure mode.

Elliptic Curve Diffie-Hellman (ECDH)

This uses elliptic curve cryptography instead of prime numbers in its computation.

Known Ciphertext Attack

Using statistical tools to attempt to discover a pattern in ciphertexts; also called Ciphertext only attack.

High Resiliency

the ability to quickly recover from these resource vs. security constraints.

Digital Signature Algorithm (DSA)

A U.S. federal government standard for digital signatures.

Blowfish

A block cipher that operates on 64-bit blocks and can have a key length from 32 to 448 bits.

Trusted Platform Module (TPM)

A chip on the motherboard of the computer that provides cryptographic services.

Pretty Good Privacy (PGP)

A commercial product that is commonly used to encrypt files and messages.

Deprecated Algorithms

A cryptographic algorithm that is still available but should not be used because of known vulnerabilities.

Hardware Security Module (HSM)

A dedicated cryptographic processor that provides protection for cryptographic keys.

Twofish

A derivation of the Blowfish algorithm that is considered to be strong.

RACE Integrity Primitives Evaluation Message Digest (RIPEMD)

A hash algorithm that uses two different and independent parallel chains of computation and then combines the result at the end of the process.

Hashed Message Authentication Code (HMAC)

A hash function used to authenticate the sender.

Confusion

A means to thwart statistical analysis so that the key does not relate in a simple way to the ciphertext.

C. ROT13

Alexei was given a key to a substitution cipher. The key showed that the entire alphabet was rotated 13 steps. What type of cipher is this? A. AES B. XAND13 C. ROT13 D. Alphabetic

Hash

Algorithm creates a unique "digital fingerprint" of a set of data.

B. confusion

Alyosha was explaining to a friend the importance of protecting a cryptographic key from cryptoanalysis. He said that the key should not relate in a simple way to the cipher text. Which protection is Alyosha describing? A. diffusion B. confusion C. integrity D. chaos

RC4

An RC stream cipher that will accept keys up to 128 bits in length.

Collision Attack

An attempt to find two input strings of a hash function that produce the same hash string.

Substitution Cipher

An category that substitutes one character for another by substituting 1 for the letter A, 2 for the letter B etc.

XOR Cipher

Another common algorithm that is based on the binary operation eXclusive OR that compares two bits: if the bits are different a 1 is returned, but if they are identical then a 0 is returned.

C. It would be essentially impossible to keep its location a secret from everyone.

At a staff meeting one of the technicians suggested that the enterprise protect its new web server by hiding it and not telling anyone where it is located. Iosif raised his hand and said that security through obscurity was a poor idea. Why did he say that? A. It is an unproven approach and has never been tested. B. It would be too costly to have one isolated server by itself. C. It would be essentially impossible to keep its location a secret from everyone. D. It depends too heavily upon non-repudiation in order for it to succeed.

Misconfiguration Implementation

Breaches of cryptography that are the result of incorrect configuration or uses of the cryptography.

Asymmetric Cryptographic Algorithms

Cryptography that uses two mathematically related keys.

Data-in-Use

Data actions being performed by "endpoint devices" such as printing as printing a report from a desktop computer.

Data-at-Rest

Data that is stored on electronic media.

Self-Encrypting Drives (SEDs)

Drives that can automatically encrypt any data stored on it

C. verify the receiver

Egor wanted to use a digital signature. Which of the following benefits will the digital signature not provide? A. verify the sender B. prove the integrity of the message C. verify the receiver D. enforce nonrepudiation

Digital Signature

Electronic verification of the sender.

Full Disk Encryption (FDE)

Encryption that protects all the data on a hard drive.

GNU Privacy Guard (GNuPG)

Free and open source software that is commonly used to encrypt and decrypt data.

Steganography

Hides the existence of the data.

C. Alice's public key

If Bob wants to send a secure message to Alice using an asymmetric cryptographic algorithm, which key does he use to encrypt the message? A. Alice's private key B. Bob's public key C. Alice's public key D. Bob's private key

Diffusion

If a single character of plaintext is changed then it should result in multiple characters of the ciphertext changing.

D. RSA

Illya was asked to recommend the most secure asymmetric cryptographic algorithm to his supervisor. Which of the following did he choose? A. SHA-2 B. ME-312 C. BTC-2 D. RSA

Diffie-Hellman (DH)

Key exchange requires Alice and Bob to each agree upon a large prime number and related integer.

Ephemeral Keys

Keys that are used only once and then discarded

Obfuscation

Making something obscure or unclear.

Random Numbers

Numbers for which there is no identifiable pattern or sequence.

Data Encryption Standard (DES)

One of the first widely popular symmetric cryptography algorithms. no longer considered secure.

ROT13

One type of substitution cipher, which the entire alphabet is rotated 13 steps: A=N, B=O, etc.

Block Cipher

Other algorithms manipulates an entire block of plaintext at one time.

Algorithm

Procedures based on mathematical formula used to encrypt and decrypt the data. also called a cipher.

A. non-repudiation

Proving that a user sent an email message is known as _____. A. non-repudiation B. repudiation C. integrity D. availability

B. perfect forward secrecy

Public key systems that generate random public keys that are different for each session are called _____. A. Public Key Exchange (PKE) B. perfect forward secrecy C. Elliptic Curve Diffie-Hellman (ECDH) D. Diffie-Hellman (DH)

Perfect Forward Secrecy

Public key systems that generate random public keys that are different for each session.

Low-Power Devices

Small electronic devices that consume very small amounts of power.

Stream Cipher

Some algorithms take one character and replaces it with one character.

Sponge Function

Takes as input a string of any length and returns a string of any requested variable length.

C. encrypts the key and the message

The Hashed Message Authentication Code (HMAC) _____. A. encrypts only the message B. encrypts only the key C. encrypts the key and the message D. encrypts the DHE key only

Cyptography

The Practice of transforming information so that it is secure and cannot be accessed by unauthorized parties.

RSA

The most common asymmetric cryptography algorithm.

Security Through Obscurity

The notion that virtually any system can be made secure so long as outsiders are unaware of it or how it functions.

Key Exchange

The process in which keys are managed by a third party, such as a trusted CA.

A. It provides cryptographic services in hardware instead of software

What is a characteristic of the Trusted Platform Module (TPM)? A. It provides cryptographic services in hardware instead of software B. It allows the user to boot a corrupted disk and repair it C. It is available only on Windows computers running BitLocker D. It includes a pseudorandom number generator (PRNG)

B. plaintext

What is data called that is to be encrypted by inputting it into a cryptographic algorithm? A. opentext B. plaintext C. cleartext D. ciphertext

B. SHA-3

What is the latest version of the Secure Hash Algorithm? A. SHA-2 B. SHA-3 C. SHA-4 D. SHA-5

Collision

When two files have the same hash.

Encryption

When using cryptography, the process of changing the original text into a scrambled message.

D. in the directory structure of the file system

Which areas of a file cannot be used by steganography to hide data? A. in areas that contain the content data itself B. in the file header fields that describe the file C. in data that is used to describe the content or structure of the actual data D. in the directory structure of the file system

C. Diffie-Hellman (DH)

Which of the following key exchanges uses the same keys each time? A. Diffie-Hellman-RSA (DHRSA) B. Diffie-Hellman Ephemeral (DHE) C. Diffie-Hellman (DH) D. Elliptic Curve Diffie-Hellman (ECDH)

B. risk loss

Which of these is NOT a basic security protection for information that cryptography can provide? A. authenticity B. risk loss C. integrity D. confidentiality

Resource vs. Security Constraint

A limitation in providing strong cryptography due to the tug of war between the available resources( time and energy) and the security provided by cryptography.

Message Digest 5 (MD5)

A revision of MD4 that was designed to address MD4's weaknesses.

Secure Hash Algorithm (SHA)

A secure hash algorithm that creates more secure hash values then message digest(MD) algorithms.

Advance Encryption Standard (AES)

A symmetric cipher that was approved by the NIST in late 2000 as a replacement for DES.

Triple Data Encryption Standard (3DES)

A symmetric cipher that was designed to replace DES. No longer considered the most secure symmetric cipher.

C. digest

A(n) _____ is not decrypted but is only used for comparison purposes. A. key B. stream C. digest D. algorithm

C. 0

Abram was asked to explain to one of his coworkers the XOR cipher. He showed his coworker an example of adding two bits, 1 and 1. What is the result of this sum? A. 2 B. 1 C. 0 D. 16

Data-in-Transit

Actions that transmit the data across a network, like an email sent across the internet.

Non-Repudiation

The process of proving that a user performed an action such as sending an email message.

Symmetric Cryptographic Algorithms

The same single key to encrypt and decrypt a document.

B. Hardware Security Module (HSM)

Which of these has an onboard key generator and key storage facility, as well as accelerated symmetric and asymmetric encryption, and can back up sensitive material in encrypted form? A. Trusted Platform Module (TPM) B. Hardware Security Module (HSM) C. self-encrypting hard disk drives (SED) D. encrypted hardware-based USB devices