UNIVERSITY EXAMINATIONS: 2021/2022
EXAMINATIONS FOR THE DEGREE OF BACHELOR OF SCIENCE IN
INFORMATION SECURITY AND FORENSICS
BISF 3107: BLOCK CHAIN TECHNOLOGIES AND APPLICATIONS
FULL TIME/PART TIME
DATE: DECEMBER, 2021 TIME: 2 HOURS
INSTRUCTIONS: Answer QUESTION ONE AND ANY OTHER TWO questions.
QUESTION ONE (20 Marks)
a) Define the following terms (5 Marks)
i) Transaction
ii) Serialization
iii) Distributed System
iv) Timestamp
v) Ledger
b) The above diagram shows metadata about the transactions included in a block. Using the
diagram as reference identify the different components of a block header and describe its
role. ( 6 Marks )
c) There are seven major tasks that need to be addressed when designing and developing a
software system that manages ownership by using a purely distributed peer-to-peer system
of ledgers in an open and untrustworthy environment. State and briefly describe any two
tasks (4 Marks)
d) What is block chain and briefly describe its application areas (5 Marks)
QUESTION TWO (15 Marks)
a) Integrity is an important nonfunctional aspect of any software system. State and describe
any two major components (5 Marks)
b) At a high level, a transaction has four components. Using the diagram below, highlight the
four components and give a brief description of the components (5 Marks)
c) Based on the properties of the block chain and its characteristic as being a generic data
store for all kinds of data, briefly describe following generic-use patterns of the block
chain: ( 5 Marks)
I. Proof of existence
II. Proof of nonexistence
III. Proof of time
IV. Proof of order
V. Proof of identity
QUESTION THREE (15 Marks)
a) Using an illustration discuss how the proof of ownership and transfer of ownership relate
to the purpose and the properties of a ledger. (6 Marks)
b) Every node, when receiving transactions, makes sure that each transaction adheres to the
network rules referred to as transaction validation. Describe the any two things that a block
checks (4 Marks)
c) Describe any five limitations of block chain (5 Marks)
QUESTION FOUR (15 Marks)
a) Using examples, briefly describe the integrity threats in peer to peer systems
(5 Marks)
b) The network handshake is how nodes establish communication in block chain. Illustrate
using a diagram how the hand shake is achieved (5 Marks)
c) Restricting reading or writing access to the history of transaction data impacts the
following aspects of the blockchain: The peer-to-peer architecture, The distributed nature
and The purpose. Briefly discuss
( 5 Marks)
