cryptography test Flashcards

(28 cards)

1
Q

What is decryption?

A

The process of converting encrypted data back to its original format

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2
Q

What does it mean to decrypt data?

A

Turning encrypted data back to its original readable form

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3
Q

Why do we want to decrypt data?

A

To make encrypted information readable and accessible to authorized individuals or systems

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4
Q

What is the difference between asymmetric and symmetric encryption?

A

Symmetric encryption uses a single key for both encryption and deception while asymmetric uses a pair of keys a public and private key

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5
Q

Caesar Cipher - uses one shift forward and the negative shift backwards

A

Type of encryption: symmetric
Why: it uses the same key for encryption and decryption

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6
Q

Polyalphabetic cipher - uses the same word for encryption and decryption but decrypts with a backwards shift

A

Type of encryption: symmetric
Why: uses the same keyword just in reverse for decryption

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7
Q

RSA encryption - uses a public and a private key for encryption and decryption

A

Type of encryption: asymmetric
Why: uses two different keys, a public for encryption and a private for decryption so the keys aren’t identical

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8
Q

Decrypt this message. The Caesar Cipher shift is 6
se skyygmk

A

my message

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9
Q

What is frequency fingerprint?

A

The unique pattern of how often each letter or symbol appears in a piece of text

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10
Q

How can we use frequency fingerprint to decrypt when we don’t know the key?

A

We can use it to decrypt a substitution cipher of letters in the ciphertext to the known letter

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11
Q

What is a way to prevent a frequency fingerprint?

A

Use a poly alphabetic cipher or a more advanced encryption method

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12
Q

Complete the polyalphabetic cipher. The key is CAB
g j h h e g

A

difede

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13
Q

History: Pick two historic uses of encryption. Explain the following: (20 pts)

A

Event 1: enigma machine
Who (used the cipher):
The Germans and later allied code breakers

What (cipher was used):
The enigma machine was a device used by the German during World War II to encrypt military communications

When ( was the cipher used):
1930s-1945 during world war II

Why (was the cipher used):
Germans use it to keep their military plans secret

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14
Q

Confidentiality, Integrity or Authenticity. A data entry clerk mistakenly inputs incorrect data into a financial system, leading to inaccurate financial reporting

A

Integrity

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15
Q

An intruder tries to access a restricted area of a government building, but is denied entry due to the biometric access control system requiring fingerprint authentication.

A

Authenticity

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16
Q

An employee accesses a company document on a public Wi-Fi network, exposing sensitive data to potential eavesdroppers.

A

Confidenciality

17
Q

A lawyer’s private conversation with a client is recorded without their knowledge through a compromised smartphone, breaching attorney-client privilege.

A

Confidenciality

18
Q

A user tries to log into a social media account, but is required to complete a two-factor authentication process, ensuring that the access is legitimate.

19
Q

A hacker modifies the source code of a company’s website, causing it to display incorrect information to its users.

20
Q

plaintext

A

Original readable data or message before encryption

21
Q

ciphertext

A

Result of encrypting plaintext

22
Q

shift

A

refers to the number of positions each keyed is moved

23
Q

Substitution cipher where each letter is mapped to its numeric equivalent encrypted message and then mapped back to a letter

24
Q

transposition cipher that encrypts a message by writing it in a zigzag pattern across multiple rows

25
poly alphabetic ciphers and consists of two rotating disks that have an alphabet written on it. Outer disk is in alphabetic order and the inner is scrambled
Alberti’s Disc
26
Rotate by 13 places. Substitution cipher where each letter of the plaintext is shifted 13 positions forward in the alphabet
ROT-13
27
tool used to encrypt messages which is a polyalphabetic substitution cipher. The cipher uses a keyword to determine the shifts making it more secure
Vigenere Square
28
electromechanical cipher machine used a series of rotating disks to perform encryption and decryption
Enigma