Explain why lossy compression is unsuitable for a program file.
From Paper 1: Computer systems
5(b)4 marks
Explain how asymmetric encryption allows two people who have never met to communicate securely.
From Paper 1: Computer systems
5(c)2 marks
Explain why passwords are stored as hashes rather than encrypted.
From Paper 1: Computer systems
5(d)8 marks
A library stores: Loan(LoanID, MemberID, MemberName, BookID, Title, Author, DateOut). (i) Explain why this is not in third normal form. (ii) Normalise it to 3NF. (iii) Write an SQL statement to list titles of books borrowed by member M104.
From Paper 1: Computer systems
5(e)2 marks
Explain referential integrity using the library database.
From Paper 1: Computer systems
5(f)2 marks
Explain atomicity and durability.
From Paper 1: Computer systems
5(g)4 marks
Explain the advantages of using a layered protocol stack such as TCP/IP.
From Paper 1: Computer systems
5(h)3 marks
Explain how DNS resolves a domain name to an IP address.
From Paper 1: Computer systems
5(i)3 marks
Compare packet switching with circuit switching.
From Paper 1: Computer systems
5(j)3 marks
Explain how firewalls and proxy servers protect a network.
Score 0 / 33 · 0 of 10 marked
This paper is written by Plasmo in the style of the OCR A-Level Computer Science exam. It is not a past paper and is not produced or endorsed by the exam board.
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