CEC 603 Information Systems and Network Security Exam 2026

About this paper

CEC 603: A 4-page First Semester Examination for Information Systems and Network Security (CEC603, credit value 6) at the University of Buea College of Technology, instructor Sone Ekonde, dated 26/02/2026, 3 hours. Question 1 (compulsory, 25 marks) covers firewall design goals, application-level and circuit-level gateways, honeypots, virus/hacker vulnerability-threat pairs, an RSA public-key-infrastructure numeric problem (N=55, computing ciphertexts and private keys for two users), and the confidentiality/integrity/availability security triad. Question 2 covers firewall configuration block diagrams (screened host single/dual-homed bastion, screened subnet), an SMTP packet-filtering permit/deny scenario, VPN/IPsec packet structure, a 7-rule packet-filter ruleset interpretation, and firewall settings for stated policies. Question 3 covers a one-way-function password-checking scheme, Anderson's-formula PIN brute-force probability and entropy calculation, and intrusion detection system (IDS) outputs, signature-based detection and NIDS/HIDS. Question 4 covers a simplified Kerberos KDC authentication exchange with numeric key/identity parameters, an RSA sign-then-encrypt scheme between Alice and Bob with full key computation, and the Biba integrity model's no-read-down/no-write-up principles applied to a worked scenario.