CNIT 270 Exam 1 (Latest Update 2026 /
2027) Questions & Answers {Grade A}
100% Correct
What are some examples of hash functions? - correct answer MD5, SHA1, SHA2, SHA3,
Rumba20
What are some examples one would using hashing for? - correct answer Proving a
message is not altered, password storage, file integrity, intrusion detection.
What is Kerckhoff's principle? - correct answer A cryptosystem should be secure even
if everything about the system, except the key, is public knowledge.
,What is symmetric encryption? - correct answer Conventional/single-key encryption.
When two entities already have a secure secret key with a strong encryption
algorithm. The key is used to both encrypt and decrypt.
What is the difference between a stream and block cipher? Which is faster? Which is
less susceptible to insertions and modifications? - correct answer Stream ciphers
encrypt one bit or byte at a time, vs how block ciphers work on larger chunks of data
at a time. Stream is faster, block is less susceptible.
What is DES? What is double, two-key triple, and three-key DES? - correct answer
Data Encryption Standard
- encrypt with one key
- encrypt with 1st key, then encrypt w/ 2nd
- encrypt with 1st key, then encrypt or decrypt w/ 2nd, then encrypt w/ 1st key again
,- encrypt w/ first key, then encrypt or decrypt w/ 2nd, then encrypt w/ 3rd key
What is AES? - correct answer Advanced Encryption Standard
- symmetric block cipher
What is ECB? - correct answer Electronic codebook. Simplest approach to multiple-
block encryption as each block is encrypted against the same key.
What are some modes of operations for symmetric encryption? - correct answer
Electronic Codebook (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB),
Output Feedback (OFB), Counter (CTR).
Which two CIA triad concepts does secret key (symmetric) encryption protect? -
correct answer Confidentiality and Integrity
, Which encryption method sings data to show authenticity and proof of origin? - correct
answer Public Key (asymmetric)
What are some threats to physical security? - correct answer Environmental threats,
technical threats, human-caused threats.
What are examples of human-caused physical security threats? - correct answer
Unauthorized physical access, theft of equipment/data, vandalism equipment/data,
misuse of resources
What is social engineering? - correct answer Using human weaknesses to obtain
information to be used in malicious ways.
What are some physical approaches to social engineering? - correct answer Dumpster
diving, shoulder surfing, tailgating
2027) Questions & Answers {Grade A}
100% Correct
What are some examples of hash functions? - correct answer MD5, SHA1, SHA2, SHA3,
Rumba20
What are some examples one would using hashing for? - correct answer Proving a
message is not altered, password storage, file integrity, intrusion detection.
What is Kerckhoff's principle? - correct answer A cryptosystem should be secure even
if everything about the system, except the key, is public knowledge.
,What is symmetric encryption? - correct answer Conventional/single-key encryption.
When two entities already have a secure secret key with a strong encryption
algorithm. The key is used to both encrypt and decrypt.
What is the difference between a stream and block cipher? Which is faster? Which is
less susceptible to insertions and modifications? - correct answer Stream ciphers
encrypt one bit or byte at a time, vs how block ciphers work on larger chunks of data
at a time. Stream is faster, block is less susceptible.
What is DES? What is double, two-key triple, and three-key DES? - correct answer
Data Encryption Standard
- encrypt with one key
- encrypt with 1st key, then encrypt w/ 2nd
- encrypt with 1st key, then encrypt or decrypt w/ 2nd, then encrypt w/ 1st key again
,- encrypt w/ first key, then encrypt or decrypt w/ 2nd, then encrypt w/ 3rd key
What is AES? - correct answer Advanced Encryption Standard
- symmetric block cipher
What is ECB? - correct answer Electronic codebook. Simplest approach to multiple-
block encryption as each block is encrypted against the same key.
What are some modes of operations for symmetric encryption? - correct answer
Electronic Codebook (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB),
Output Feedback (OFB), Counter (CTR).
Which two CIA triad concepts does secret key (symmetric) encryption protect? -
correct answer Confidentiality and Integrity
, Which encryption method sings data to show authenticity and proof of origin? - correct
answer Public Key (asymmetric)
What are some threats to physical security? - correct answer Environmental threats,
technical threats, human-caused threats.
What are examples of human-caused physical security threats? - correct answer
Unauthorized physical access, theft of equipment/data, vandalism equipment/data,
misuse of resources
What is social engineering? - correct answer Using human weaknesses to obtain
information to be used in malicious ways.
What are some physical approaches to social engineering? - correct answer Dumpster
diving, shoulder surfing, tailgating
