Computer Security: Key Distribution and Malicious Code Threats

Running head: COMPUTER SECURITY
Assignment 2: COMPUTER SECURITY
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COMPUTER SECURITY 2
Question 1: Key distribution
Part A
KDC is used to share a unique key which is to be used by each and every party. In this
case, N1 is appended, to exchange message so as to protect the logical connection between A and
B. The KDC has to first to identify both A and B and their unique nonce N1.
Part B
There are five steps required for mutual authentication these are;
a) Initiator A first requests the KDC a session key so as to protect logical connection to
respondent B
b) The KDC then responds to initiator A with a message that is encrypted using Ka which
includes one-time session keys which are to be used for session
c) A then stores the key to be used later. A then forwards to respondent B the information or
data from KDC for B which are named, E(Kb, [K8 || IDA]).
d) Using now the new session key for encryption respondent then sends a nonce N2 to
initiator A
e) By using Ks, initiator A responds using f(N2).
Part C
If master keys such as Kb and Ka are comprised by an adversary, it means that
cryptographic capabilities are comprised. One of the comprised security capability is
confidentiality. This means that information on transit has been comprised by the hackers or
anyone with bad intention. Another security capability comprised are authentication meaning
that an unauthorized person can impersonate as an authorized one. Third, digital date and time
stamp are comprised meaning that the digital date and time stamp is wrong.