Reference no: EM133076834

CIS4017-N Systems Administration and Security - Teesside University

Assignment - Cryptography basics, security analysis, design and implementation

Part 1 - Cryptography question

1. Using the Vigenere (polyalphabetic) cipher, encrypt the message MYSIMPLEENCRYPTION using the key CNET

2. Decrypt OHW PHR XWC CC using the Caesar cipher (shift of 3).

RSA

3. Assume a public key for RSA encryption given by the pair (143,11). Find the private key corresponding to this pair.

4. Using the pair (143, 11), decode the encrypted message (111 4 88 57 116 67) assuming the letters were represented by ASCII values (recall that the ASCII values are 65->A, 66->B, ... and 97->a, 98->b, ...)

Diffie-Hellman protocol

5. Describe in detail the Diffie-Hellman protocol for three parties Alice, Bob and Carol.

Part II Security analysis and design

Case Scenario 1 - Security models

ABC Ltd. is a company providing security solutions to public services. You are asked to help the ABC Ltd to design a security model for the national defence department - a part of an e-government project on secure information control in managing troops. Assume the armed forces be classified as: {army, navy, air force, marines}, the security levels are typed as: {high, low}.

Your tasks: You should produce a short report (around 500 words) to formalise a Bell Lapadula model to address the confidentiality properties for the specified scenario, and to discuss the strength and weakness of your model.

Hint: You need to describe the model (specify subjects, objects, possible operations - which can be flexible, design your own but need to show your understanding of specifying and applying the BLP model in a real case), the security lattice (a graph can be helpful), the policy and the security properties for the given scenario above.

Case Scenario 2 - Security Analysis and Solutions to Conference Management Systems

A conference manage system is a web-based management system which allows researchers submit research papers, the program committee (PC) members (reviewers) to browse papers and contribute reviews, scores and discussion, and release decisions (such as rejection or accept) via the Web. In one arrangement, the conference chair downloads and hosts the appropriate server software. (A good example is easychair:

The system allows users to submit papers, enter reviews & scores and access reviews & scores associated with events (conferences or workshops) regarding to the role of the uses. A user is granted access to the system by providing a role (chair, reviewer, or author) along with a user-id and associated password. Permissible roles for each user are specified at the time a new event is added to the management system. Reviews & scores on papers are initially assigned by chairs (chairs assign papers to reviewers for reviewing, one reviewers can be assigned multiple papers, one paper can be allocated to multiple reviewers). Reviewing are done by reviewers. And a chair can perform any and/or all of these actions, but a chair's updates can only be changed by the chair. An author, in addition to learning about his or her reviews & grades on individual papers, is entitled to learn the acceptance statistics (but not other papers' reviews), and the conference program.

Threat model: The adversary is a user who desires to learn the reviews & scores, changes reviews & scores, or prevent others from learning or changing reviews & scores. The adversary has access to the management system and also can read, delete, and/or update network messages in transit. The adversary cannot physically access or run programs on a user's machine that is running a browser to access the management system. And the adversary can not physically access or run programs on the server hosting the management system.

Your tasks: You are asked to produce a report (1500-2000words) to provide contemplate descriptions of the above Web-based Conference Management System and identify the following:

1. Assets and security properties: what objects should be protected, what security properties might we expect the system to enforce? For each such security property, label it with one of: confidentiality, integrity, or availability?

2. Vulnerability: explain the vulnerability in the system and use an attack tree/model to describe how an attack could be mounted. Restrict your consideration to the threat model provided.

3. Protection: explain what cost-effective protections are available against the threats that you identify. Remember the focus is on software vulnerabilities.

Hint: Assuming that the manager is not a technical person, craft your explanation in a way that can be explained to a layman and include figures where necessary.

Case Scenario 3- Design and Implementation of a Secure Network

This task involves designing and implementing an Internet-connected secure network for a medium- sized company requiring 500 machines named Smith Logistics, UK. They want to implement a secure network that uses Class C network address with multiple subnets - They have asked you for a price quote as well. But they want to see a packet tracer implementation and simulation results before they commit to purchasing anything.

You can use Packet tracer/Opnet/Omnet++ for the implementation and security measures. The implementation of the network should consist of core, distribution and access layer.

It should use a minimum of two routers at the distribution and a further 2-4 for the core layer. All router interfaces must be tested for the correct subnet operations.

Your tasks: You should write a report with the appropriate design and implementation solution (2500 words max, but flexible) documenting all that you have done, including how the network is set up. Use the tasks below as a guideline to write.

1. Using a drawing tool of your choice design the network. Draw a simple network diagram of your network.
Hints: Design the logical diagram. You can ignore the device location in a logical design. Use Visio or any drawing tool for the diagram. Don't forget to label the diagram core, access and distribution layer.

2. Design and Implement an IPv4 subnetting scheme. You can use any address in class c.

3. Hint: Test a small subsection of the network before implementing the full addressing scheme in packet tracer.

4. The report must describe the design and all of the decisions that you have made in the process of developing the design. This will include a discussion of the design model, Security, WAN protocol, Layer 2, 3 and wireless protocols that you have decided to use. Hint: Restrict your discussion to the main layer 1,2 and 3 protocols

5. Show the detailed cost of implementing your solution in a table format. You can try to show two different costs for the company to choose from.
Hints: Research on the costs of servers (hardware and software), switches, workstations, cables, etc.

6. Show all references used in the report, using appropriate referencing.

Hints: Harvard referencing can be used and make sure the format is fully followed.

Attachment:- Systems Administration and Security.rar