Quiz Cryptographic Solutions
- Which term describes the original, unencrypted data before any cryptographic process has been applied?
A) Ciphertext
B) Plaintext
C) Hash Digest
D) Key Space
- In symmetric encryption, which of the following is true regarding the keys used by the sender and receiver?
A) The sender uses a public key and the receiver uses a private key.
B) Both parties use the exact same secret key.
C) The keys are mathematically related but different.
D) No keys are required for symmetric encryption.
- What is the primary disadvantage of using asymmetric encryption for bulk data transfer?
A) It is less secure than symmetric encryption.
B) It requires a shared secret key to be exchanged first.
C) It is computationally expensive and slow.
D) It cannot provide non-repudiation.
- Which cryptographic concept ensures that data has not been tampered with during transit?
A) Confidentiality
B) Obfuscation
C) Integrity
D) Availability
- A digital signature is created by combining which two cryptographic elements?
A) Symmetric key and Hashing
B) Asymmetric key and Hashing
C) Public key and Private key
D) Salting and Key Stretching
- Why is AES-256 considered significantly more secure than AES-128?
A) It is twice as strong because the key is twice as long.
B) It has a trillions of times larger key space (2 256 vs 2 128 ).
C) It uses a different algorithm entirely.
D) It is an asymmetric algorithm while AES-128 is symmetric.
- Which entity is responsible for issuing and validating digital certificates in a PKI?
A) Registration Authority (RA)
B) Certificate Authority (CA)
C) Key Escrow
D) Root User
- What is the primary purpose of "Salting" a password before hashing it?
A) To make the password easier for the user to remember.
B) To prevent attackers from using pre-computed Rainbow Tables.
C) To encrypt the password so it can be decrypted later.
D) To reduce the amount of storage needed for passwords.
- Which data state refers to information stored on a hard drive that is not currently being accessed?
A) Data in Transit
B) Data in Use
C) Data at Rest
D) Data in Processing
- What is "Steganography"?
A) Scrambling data into unreadable ciphertext.
B) Hiding a message within another file, such as an image.
C) Strengthening a weak password using multiple rounds of hashing.
D) A decentralized ledger for transactions.
Answer Key & Explanations
B) Plaintext. Plaintext is the raw information; Ciphertext is what you get after encryption.
B) Both parties use the exact same secret key. "Symmetric" means the same on both sides. This makes it fast but requires a secure way to share the key.
C) It is computationally expensive and slow. Because of the complex math (prime numbers), asymmetric encryption is usually used to encrypt keys, while symmetric is used for the actual files.
C) Integrity. Integrity means the data is "whole" and unchanged. This is usually verified using a hash.
B) Asymmetric key and Hashing. You hash the file to ensure integrity, then encrypt that hash with your Private Key to prove who you are (non-repudiation).
B) It has a trillions of times larger key space. Adding just one bit doubles the combinations. Adding 128 more bits makes it exponentially harder to brute-force.
B) Certificate Authority (CA). The CA is the "Trusted Third Party" (like GoDaddy or DigiCert) that signs the certificate.
B) To prevent attackers from using pre-computed Rainbow Tables. A salt is a random value added to a password so that two people with the same password ("Password123") end up with completely different hashes.
C) Data at Rest. This is data on HDDs, SSDs, or USBs. "In Transit" is on the wire/network; "In Use" is in RAM.
B) Hiding a message within another file. Unlike encryption (which hides the meaning), steganography hides the existence of the message entirely.