4th form IT Q1 Final Exam Review

What is the primary purpose of encryption?

• To make files smaller

• To hide the original message from unauthorized people

• To speed up internet connections

• To create new cryptocurrencies

Answer explanation

The primary purpose of encryption is to hide the original message from unauthorized people, ensuring that only intended recipients can access the information.

A Caesar Cipher is an encryption technique that:

• Uses two different keys

• Shifts the alphabet by a fixed number of characters

• Maps each letter to a random other letter

• Creates a digital signature

Answer explanation

A Caesar Cipher shifts the alphabet by a fixed number of characters, making it a simple substitution cipher. The other options do not accurately describe this technique.

What is a "key" in cryptography?

• A button on a keyboard

• A physical key for a lock

• A secret password for locking and unlocking a message

• A type of computer virus

Answer explanation

In cryptography, a "key" refers to a secret password used for locking and unlocking messages, ensuring that only authorized parties can access the information. This distinguishes it from physical keys or unrelated terms.

The process of unscrambling a message is called:

• Encryption

• Hashing

• Decryption

• Mining

Answer explanation

The process of unscrambling a message is known as decryption. It involves converting encoded or encrypted data back into its original form, making it readable again.

When the same key is used to encrypt and decrypt a message:

• Asymmetric Encryption

• Public Key Encryption

• Symmetric Encryption

• Blockchain

Answer explanation

Symmetric Encryption uses the same key for both encryption and decryption, making it distinct from Asymmetric and Public Key Encryption, which utilize a pair of keys. Blockchain is unrelated to encryption methods.

The key that is shared with everybody is called a:

• Private Key

• Public Key

• Master Key

• Secret Key

Answer explanation

The key that is shared with everyone is known as a Public Key. It allows secure communication and encryption, contrasting with a Private Key, which is kept secret and used for decryption.

A unique representation of a message is called a:

• Nonce

• Message Signature

• Message Hash

• Ledger

Answer explanation

A message hash is a unique representation of a message, created by applying a hash function. It ensures data integrity and is used in various applications, including digital signatures and blockchain technology.

What is a "ledger" in the context of blockchain?

• A number used once

• A type of computer hardware

• A record of all transactions in a group

• A secret key

Answer explanation

In blockchain, a "ledger" refers to a record of all transactions within a group. It serves as a decentralized database that ensures transparency and security, making it the correct choice among the options provided.

When enough people agree on something, is called:

• Proof of Work

• Mining

• Hashing

• Consensus

Answer explanation

When enough people agree on something, it is referred to as 'Consensus'. This term is commonly used in various fields, including decision-making and blockchain technology, to indicate a general agreement among participants.

What is "mining" in the context of blockchain?

• Digging for physical coins

• Solving complex puzzles to verify transactions

• Selling cryptocurrencies on an exchange

• Creating a new encryption key

Answer explanation

In blockchain, "mining" refers to the process of solving complex puzzles to verify transactions and add them to the blockchain. This ensures the integrity and security of the network, making it the correct choice.