CSC 2045 Cryptography Week 6 Quiz

The practice of hiding information using mathematical algorithms to make it unreadable without a key.

The process of converting plain text into an unreadable format using a specific algorithm.

The reverse process of encryption, restoring an encrypted message back to its original form using a key.

A simple substitution cipher where each letter is shifted by a fixed number of positions in the alphabet.

A statistical analysis technique used to break simple substitution ciphers by observing the frequency of letters in ciphertext.

A cipher where each letter is shifted by a different amount based on a secret key.

The use of a one-time pad, a randomly generated key, to encrypt a message. It's considered unbreakable if used correctly.

A type of encryption technique where the same key is used for both encryption and decryption.

The process of trying all possible keys to decrypt a message.

A type of encryption technique where different keys are used for encryption and decryption.

Attackers can see private data sent over the internet, such as emails, passwords, and tax documents. Encryption scrambles this data to hide its meaning, making it unreadable without a secret key.

Encryption turns plain text into an unrecognizable mess, making it difficult for attackers to understand the data.

Public key encryption uses separate keys for encryption and decryption, making it more secure but slower.

Public key encryption ensures only the intended recipient can decrypt the message, while symmetric encryption relies on the sender and receiver knowing the same key.

It occurs when a message is encrypted using a Caesar Cipher and you know the original message. This allows you to figure out the shift amount used to encrypt the message.

A type of cipher where each letter is shifted by a fixed amount in the alphabet. An example is shifting each letter by 3 positions. 'A' becomes 'D', 'B' becomes 'E', and so on.

A type of cipher that uses a word as the shift key, allowing for different shifts for each letter. The shift key is repeated to match the length of the message, and the shift is determined by the corresponding key letter.

The Vigenère cipher uses a table to look up the encrypted letter based on the original letter and the shift key letter.

A substitution cipher can be cracked by examining the frequency of letters in the ciphertext and comparing it to the expected frequency of letters in the original language.

A codebook is a simple list of mappings between words, sentences, or phrases and shorter groups of symbols. It's used in coding systems to save time by replacing long messages with shorter codes.

Codes involve mapping meaningful units like words or phrases to shorter symbols, while ciphers are purely mechanical operations, often applying complex mathematical logic to individual letters or small groups of letters.

A shift cipher is a simple type of encryption where each letter in the alphabet is shifted by a fixed number of positions. For example, the letter 'A' could be shifted to 'D' in a shift of three.

Ciphers operate on individual letters or small groups of letters, without considering meaning. They use algorithms to manipulate the characters themselves.

A bitwise operation that outputs a 1 only if one of the inputs is 1, and both are not 1. It's like an exclusive 'or' - one or the other can be true, but not both.

The process of converting a message into an unreadable format using a specific algorithm and key.

A method of encrypting a message using a randomly generated key that is as long as the message itself. It's considered unbreakable if the key is truly random and used only once.

A way to represent colors by mixing different amounts of red, green, and blue light. Each color component is assigned a number from 0 to 255, where 0 is off and 255 is full intensity.

A representation of a number using only the digits 0 and 1.