hw2_sol_Security

Hw2_sol_Security - CSC474/574 Information Systems Security Homework 2 Solutions Sketch 1 Problem 3 on page 236(Multiple KDC Domains Alice KDCA let

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CSC474/574 - Information Systems Security Homework 2 Solutions Sketch October 24, 2004 1. Problem 3 on page 236 (Multiple KDC Domains) Alice KDC A : let me talk to KDC A KDC A generates key K aC KDC A KDC C : K A - C (talk to Alice; use key K aC ) KDC A Alice : K Alice (use key K aC ) Alice KDC C : let me talk to KDC B KDC C generates key K aB KDC C KDC B : K B - C (talk to Alice at A; use key K aB ) KDC C Alice : K aC (use key K aB ) Alice KDC B : let me talk to Boris KDC B generates key K ab KDC B Boris : K Boris (talk to Alice at A; use key K ab ) KDC B Alice : K aB (use key K ab ) 2. Problem 2 on page 255 (Eavesdropping) Let r be the no. of passwords in the list, q be the no. of passwords re- quested on each login, and s the no. of logins that have been eavesdropped on. Then the probability that the eavesdropper knows all q passwords for the next login is approximately [1 - (1 - q/r ) s ] q . For q = 1, the probability is roughly 1 - e - s/r . For values of s for which this probability is reasonably
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/03/2008 for the course CSC 574 taught by Professor Ning during the Spring '04 term at N.C. State.

Page1 / 2

Hw2_sol_Security - CSC474/574 Information Systems Security Homework 2 Solutions Sketch 1 Problem 3 on page 236(Multiple KDC Domains Alice KDCA let

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online