Computer Laboratory

Dr Daniel R. Thomas

Supervising - Security I

Prerequisite material

I have produced a worksheet with solutions covering prerequisite mathematics for Security I. This is a new worksheet and there are likely to be bugs, please report them and make suggestions for improvements. There may be cake or similar for those who do so. This is strictly optional, only the probability material is required for the current Security I course, the rest is required for Security II. The source code is available.

Supervision questions last updated for 2016-2017.

If you write a program to solve any of these exercises I want to see the source code.

Supervision 1 - lectures 1-4: Cryptography, classic ciphers, block ciphers

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In order to communicate securely about supervisions we need a way of authenticating emails. All electronic submissions should be signed using your GPG key and encrypted to my work key 5017 A1EC 0B29 08E3 CF64 7CCD 5514 35D5 D749 33D9. This is an opportunity to learn to use encryption in a controlled environment so please do this properly we can discuss this at the start of the first supervision. You should submit an explanation of what you did to create and publish a key with your answers.

Exercises 1-4, 6-8 from Markus's exercise sheet.

Supervision 2 - lectures 5-7: Cryptography, Entity authentication, Access control

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Exercises: 9, 11, 12, 14, 17, 18, 23, 24 and 26.

Supervision 3 - lectures 8-12: Operating system, software and network security; revision

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Exercises: 19-21, 31, 2004 Paper 3 Question 9, "Do software updates increase or decrease risk of successful attack?" and (3.21 from p109 1st Edition or 3.29 from p106 2nd Edition) of "Introduction to Modern Cryptography" by Jonathan Katz and Yehuda Lindell: Given two encryption schemes one of which is CPA secure (you don't know which) construct a scheme out of them which is CPA secure giving a full proof of your answer.