Security, privacy and data integrity：练习题

A data entry system for a school requires a student's age to be entered as a whole number between \(11\) and \(18\). Which data validation method is most appropriate for this requirement?

In a data transmission system, block parity (two-dimensional parity) is used with even parity to ensure data integrity. The following block of data is received, where the rightmost bit of each row is the row parity bit and the bottom row contains the column parity bits:

Row 1: 1 1 0 1 | 1
Row 2: 0 1 1 1 | 1
Row 3: 1 0 0 1 | 1
Row 4: 0 1 0 0 | 1
-----------------
Parity: 0 1 0 1 | 0

Which statement correctly identifies the status of the data integrity for this block?

A data entry system uses a check digit to ensure accuracy. For a four-digit number, the check digit is calculated by summing the four digits and finding the remainder when the total is divided by \(9\). If a user enters the digits \(5, 8, 2, \text{ and } 1\), what is the resulting check digit?

To ensure non-repudiation and authenticity when sending a message, a digital signature is used. Which key must the sender use to encrypt the message digest?

Define the term 'data integrity' and state one method used to maintain it during data entry.

In the context of asymmetric encryption, explain how a sender uses a digital signature to provide non-repudiation and why the recipient must use the sender's public key to verify it.

Security, privacy, and integrity are fundamental concepts in data management. Although they are related, each term has a distinct meaning in Computer Science.

(a) Define the terms data security and data privacy, and explain the primary difference between them.

(b) Explain how the use of access rights and encryption contribute to maintaining the security of data stored on a multi-user network.