Koofers

Past Exam for CMSC 414 - CMPTR & NETWORK SECURITY with Shankar at Maryland (UMD)

Exam Information

Material Type:Exam 1
Professor:Shankar
Class:CMSC 414 - CMPTR & NETWORK SECURITY
Subject:Computer Science
University:University of Maryland
Term:Spring 2006
Keywords:
  • Particularly
  • Requirement
  • Relatively Prime
  • Environment
  • The Environment
  • The Message
  • Authentication
  • The Internet
Login / Sign Up to View Document
Preview Page 1Preview Page 2Preview Page 3Preview Page 4

Sample Document Text

CMSC 414 S06 Exam 1 SOL-KEY Page 1 of 4 Name:_________________________ SOLUTION AND GRADING KEY _____________________________________________________________________________________ Total points: 30. Total time: 115 minutes. 4 problems over 4 pages. No book, notes, or calculator 1. [10 points] Suppose Bob uses RSA with n=77 and e=5. Are these valid numbers for RSA. Explain. If you answer yes, obtain the corresponding d. _____________________________________________________________________ There are two requirements: square4 n must be a product of two primes [1 point] square4 e must be relatively prime to ?(n) (so that d, which equals e?1 mod-n, exists) [1 point] First requirement [2 points] n = 77 = 7?11. 7 and 11 are primes. So this holds. Second requirement [6 points] Recall that if n = p1a1 ? p2a2 ? ? ? pkak where pi is prime, then ?( p1a1 ? p2a2 ? ? ? pkak ) = (p1?1)?p1a1?1 ? (p2?1)?p2a2?1 ??? (pk?1)?pkak?1 So ?(77) = (7?1)?(11?1) = 60. e...

Related Documents

Particularly Exam
Particularly Exam
Particularly Exam
Particularly Exam
Particularly Exam
Particularly Notes
Authentication Notes
Authenticates Exam
Distance Learning Exam
Infrastructure Notes
Authenticates Exam
Authenticates Exam
Authenticates Notes
Requirement Notes
Application Notes
Proximity Seeking Notes
155, "/var/app/current/tmp/"