Cryptography Fundamentals Quiz

AES Key Length

• AES uses a 128-bit key length.

SHA-1 Hash Value

• SHA-1 produces a 160-bit hash value.

Diffie-Hellman Algorithm

• The Diffie-Hellman algorithm is used for one-time session key exchange.

Encryption Algorithm Input

• The input of an encryption algorithm is plaintext.

Mailboxes and Access Control

• Mailboxes are an example of an object in access control.

Transposition Cipher Example

• AES is an example of a simple transposition cipher.

Man-in-the-Middle Attack

• A man-in-the-middle attack targets symmetric key algorithms or public-key algorithms.

Data Encryption Standard (DES) Key Size

• The key size of the Data Encryption Standard (DES) is 56 bits.

Password Cracking - Traditional Approach

• The traditional approach to password cracking is password guessing.

User Education and Password Vulnerability

• User education is part of addressing password vulnerability.

DES Algorithm Rounds

• DES uses 10 rounds.

Random Numbers and Stream Keys

• Random numbers are used to generate stream keys for symmetric stream ciphers.

Asymmetric Key Encryption

• Asymmetric key encryption uses different keys for sender and receiver.

Hash Function Applicability

• Hash functions can be applied to any sized data streams.

Specific Account Attack

• Specific account attacks target specific accounts within a system.

Replay Attacks

• Replay attacks involve repeating a previously captured user response.

Security Attack Types

• Attempts to alter system resources or affect their operation is a security attack.

Block Cipher Operation Modes

• Cipher Block Chaining (CBC), Cipher Feedback (CFB), and Counter (CTR) are block cipher operation modes.

Encryption Algorithm Scenarios

• Inputs to encryption algorithms include the XOR of 64 bits of plaintext and the preceding ciphertext to produce pseudorandom output.

Security Concepts and Notations

• Matching different security scenarios with corresponding security concepts and notations (e.g., Digital Signature Standard (DSS), Message Authentication).

RSA Key Generation Steps

• Finding n (n= p*q where p and q are prime numbers)
• Calculating (n) (φ(n) = (p-1)(q-1))
• Choosing e (e is relatively prime to (n))
• Calculating d (d*e mod (n) =1)

Diffie-Hellman Key Exchange

• Agreement on a modulus (q) and a primitive root (a) as initial parameters
• User A chooses a private key (XA) and calculates a public key (YĀ)
• User B chooses a private key (XB) and calculates a public key (Yв)
• Each user calculates the shared secret key using the other user's public key

One-Time Pad Encryption

• Plaintext is XORed with a key to produce ciphertext.

Hash Function Properties

• A hash function that is infeasible to find x such that H(x)=h is called pre-image resistant.

SHA-1 Hash Output

• SHA-1 produces a 160-bit hash output.

Block Cipher Modes and Chaining

• Cipher Block Chaining (CBC) mode, each previous cipher block is chained with the current plaintext block

Virus Stages

• Viruses move through dormant, triggering, propagation, and execution stages.

Hash Function Collision Resistance

• Hash functions satisfy the property of infeasibility of finding any x, y such that (H(y)=H(x))

Public Key Encryption Algorithm

• RSA is an example of a public key encryption algorithm.

Digital Signature Functionality

• A digital signature is used for authenticating both source and data integrity, and to protect against eavesdropping, and not for confidentiality.

Types of attacks

• The most common attacks include the man-in-the-middle attacks and chosen ciphertext attacks.

Substitution and Transposition Ciphers

• A substitution cipher replaces one symbol with another. An example is Caesar cipher, and a transposition cipher rearranges the order of symbols in an example is AES.

Key Length of AES

• The key length for AES is 128 bits.

Message Authentication

• MAC stands for Message Authentication Code.

Encryption

• It's concerned with converting plaintext to ciphertext, in which sender uses the hash function, and then encrypts the hash value with the sender's private key.

Hash Functions

• Hash functions, like SHA-1, are used for integrity. In this example, SHA-1 produces a 160-bit hash value

Security Concepts

• Security concepts, such as protection domains, true random numbers, and pseudorandom numbers are used for security, as well as Diffie-Hellman, key exchange, and public keys.

Scenario Matching

• Different security scenarios are matched with appropriate security concepts and related notations.

Security Threats

• Different situations are described and matched with security threats such as disruption, usurpation, disclosure, deception, worms, and rootkits.

RSA Algorithm Steps

• To generate RSA keys, Alice or Bob choose two distinct large prime numbers, p and q. Calculate n as their product, and (n) as (p – 1) * (q – 1). Then, select an integer "e" that is relatively prime to (n), and finally, calculate integer "d" such that (d*e ) mod (n) =1. The public key is (e, n), and the private key is (d, n) .

Encryption and Decryption steps

• To encrypt a message, the sender converts the numerical value of the plaintext into a numerical value, and then raises that numerical value to the power e, where e is the encryption exponent, and then mod's that result by n, the public modulus.
• To decrypt, the receiver raises the ciphertext to the power of d, where d is the decryption exponent, modulo n. The result will be the original plaintext.