Chapter 2: Error Detection

What is the purpose of a check digit in data transmission?

• To encrypt data
• To identify errors in data entry
• To convert data into ciphertext
• To compress data

What is the main benefit of using a USB connection for data transmission?

• Reduced risk of data corruption
• Compatibility with various devices
• Increased data security
• Faster data transfer speeds

Which encryption method uses a public key for encryption and a private key for decryption?

• Public key encryption
• Asymmetric encryption
• Block cipher encryption
• Symmetric encryption

Which encryption method uses public and private keys for encryption and decryption?

• Symmetric encryption
• Asymmetric encryption
• Same key encryption
• Block cipher encryption

What is the purpose of an Automatic Repeat Request (ARQ) in data transmission?

• To verify data integrity
• To encrypt data
• To compress data
• To request re-transmission of data

Which error checking technique involves positive and negative acknowledgements?

• Parity check
• Echo check
• Automatic Repeat Request
• Checksum

How does a checksum work in error detection?

• By calculating a value from a block of data
• By adding all the digits together
• By comparing two calculated values
• By sending an extra bit with each byte

What is the purpose of a checksum in error detection?

• To calculate a value from a block of data
• To ensure even or odd number of 1s in a byte
• To add extra bits to a byte
• To compare two calculated values

What is the main drawback of symmetric encryption?

• It is rarely used anymore
• It is very complex and time consuming
• The value of the key reads the same in both directions
• There is a security problem when transmitting the encryption key

How does a check digit help identify errors in data entry?

• By multiplying all the digits by 3
• By dividing the digits by 10
• By comparing the remainder to a calculated value
• By adding all the even digits together