Cyber Security Exam 2 2026 With 100%
Accurate Answers
Cryptography - Precise Answer ✔✔protects information even
when it is not under your physical control
Uses of Encryption - Precise Answer ✔✔Privacy, Authenticity,
Integrity, Nonrepudiation
Nonrepudiation - Precise Answer ✔✔Positive proof that a
message or action originated with a certain party
Process of Encryption - Precise Answer ✔✔Key & Plaintext in
Algorithm which creates a ciphertext
Kerckhoff's Principle - Precise Answer ✔✔We assume that
threats are familiar with how our cryptography works
All security rests in a secret key
Types of Cryptanalysis - Precise Answer ✔✔Known Ciphertext,
or Ciphertext Only
All we know is the ciphertext
Most difficult situation, but common
Known Plaintext
We know the plaintext to match some of the ciphertext
encrypted with a particular key
Chosen Plaintext
We can choose some plaintext to encipher with our victim's
cipher, and retrieve the ciphertext
, Replace each letter in a text by the 3rd letter following it in the
alphabet - Precise Answer ✔✔Caesar Cipher
Uses a series of different rotations
The "key" may be a word - each letter indicates a rotation -
Precise Answer ✔✔Vignère Ciphers
Encrypted telegram from foreign secretary of the German
empire to German ambassador in Mexico - Precise Answer
✔✔Zimmerman Telegram
Enigma Machine - Precise Answer ✔✔Replaced letters as they
were typed
Substitutions were computed using a key and a set of switches
and rotors
Computer-Based Encryption - Precise Answer ✔✔DES and
AES
DES supported how many bits - Precise Answer ✔✔56-bits
AES supported how many bits - Precise Answer ✔✔128 bits,
192 bits and 265 bits
Key stream - Precise Answer ✔✔It is a stream of bits with these
properties:
Attackers can't predict its contents in practice
All trusted recipients either
have a copy of the same key stream, or
Accurate Answers
Cryptography - Precise Answer ✔✔protects information even
when it is not under your physical control
Uses of Encryption - Precise Answer ✔✔Privacy, Authenticity,
Integrity, Nonrepudiation
Nonrepudiation - Precise Answer ✔✔Positive proof that a
message or action originated with a certain party
Process of Encryption - Precise Answer ✔✔Key & Plaintext in
Algorithm which creates a ciphertext
Kerckhoff's Principle - Precise Answer ✔✔We assume that
threats are familiar with how our cryptography works
All security rests in a secret key
Types of Cryptanalysis - Precise Answer ✔✔Known Ciphertext,
or Ciphertext Only
All we know is the ciphertext
Most difficult situation, but common
Known Plaintext
We know the plaintext to match some of the ciphertext
encrypted with a particular key
Chosen Plaintext
We can choose some plaintext to encipher with our victim's
cipher, and retrieve the ciphertext
, Replace each letter in a text by the 3rd letter following it in the
alphabet - Precise Answer ✔✔Caesar Cipher
Uses a series of different rotations
The "key" may be a word - each letter indicates a rotation -
Precise Answer ✔✔Vignère Ciphers
Encrypted telegram from foreign secretary of the German
empire to German ambassador in Mexico - Precise Answer
✔✔Zimmerman Telegram
Enigma Machine - Precise Answer ✔✔Replaced letters as they
were typed
Substitutions were computed using a key and a set of switches
and rotors
Computer-Based Encryption - Precise Answer ✔✔DES and
AES
DES supported how many bits - Precise Answer ✔✔56-bits
AES supported how many bits - Precise Answer ✔✔128 bits,
192 bits and 265 bits
Key stream - Precise Answer ✔✔It is a stream of bits with these
properties:
Attackers can't predict its contents in practice
All trusted recipients either
have a copy of the same key stream, or
