Security chapter 3

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

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

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

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

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. 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)

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. 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

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

A. non-repudiation

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

C. digest

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

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.

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

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

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

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

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

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.

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. 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

Cyptography

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

Steganography

Hides the existence of the data.

Encryption

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

Algorithm

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

Substitution Cipher

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

ROT13

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

Random Numbers

Numbers for which there is no identifiable pattern or sequence.

Pseudorandom Number Generator (PRNG)

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

Diffusion

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

Confusion

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

Non-Repudiation

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

Obfuscation

Making something obscure or unclear.

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.

Data-in-Use

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

Data-in-Transit

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

Data-at-Rest

Data that is stored on electronic media.

Low-Power Devices

Small electronic devices that consume very small amounts of power.

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.

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.

High Resiliency

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

Stream Cipher

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

Block Cipher

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

Hash

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

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.

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.

Symmetric Cryptographic Algorithms

The same single key to encrypt and decrypt a document.

Data Encryption Standard (DES)

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

Triple Data Encryption Standard (3DES)

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

Advance Encryption Standard (AES)

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

RC4

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

Blowfish

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

Twofish

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

Asymmetric Cryptographic Algorithms

Cryptography that uses two mathematically related keys.

Public Key

An asymmetric encryption key that does not have to be protected

Private Key

An asymmetric encryption key that does have to be protected.

RSA

The most common asymmetric cryptography algorithm.

Elliptic Curve Cryptography (ECC)

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

Digital Signature

Electronic verification of the sender.

Digital Signature Algorithm (DSA)

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

Key Exchange

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

Diffie-Hellman (DH)

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

Diffie-Hellman Ephemeral (DHE)

A Diffie-Hellman key exchange that uses different keys

Ephemeral Keys

Keys that are used only once and then discarded

Elliptic Curve Diffie-Hellman (ECDH)

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

Perfect Forward Secrecy

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

Known Ciphertext Attack

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

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.

Deprecated Algorithms

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

Misconfiguration Implementation

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

Collision

When two files have the same hash.

Collision Attack

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

Birthday Attack

A statistical phenomenon that makes finding collisions easier.

Pretty Good Privacy (PGP)

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

GNU Privacy Guard (GNuPG)

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

Full Disk Encryption (FDE)

Encryption that protects all the data on a hard drive.

Self-Encrypting Drives (SEDs)

Drives that can automatically encrypt any data stored on it

Trusted Platform Module (TPM)

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

Hardware Security Module (HSM)

A dedicated cryptographic processor that provides protection for cryptographic keys.

Sponge Function

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