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

Exam Information

Material Type:Exam 1
Subject:Computer Science
University:University of Maryland
Term:Fall 2007
  • Particularly
  • Explanation
  • Authentication
  • Conjunction
  • The Message
  • Destination
  • Total Number
  • Infrastructure
  • Initialization
  • Relatively Prime
Login / Sign Up to View Document
Preview Page 1Preview Page 2Preview Page 3Preview Page 4Preview Page 5Preview Page 6

Sample Document Text

CMSC 414 F07 Exam 1 SOLUTION Page 1 of 11 Name:___________________ _____________________________________________________________________________________ Total points: 60. Total time: 75 minutes. 6 problems over 7 pages. No book, notes, or calculator 1. [14 points] Are n=323 and e=5 valid numbers for RSA. Explain. If you answer yes, obtain the corresponding d. _____________________________________________________________________ Solution There are two requirements: square4 n must be a product of two primes square4 e must be relatively prime to ?(n) (so that d, which equals e?1 mod-n, exists) First requirement [2 points] n = 323 = 1719. 17 and 19 are primes. So this holds. Second requirement [4 points] Recall that if n =pq where p and q are distinct primes, then ?(p?q) = (p?1)?(q?1) So ?(323) = (17?1)?(19?1) = 288. e, which equals 5, is relatively prime to 288 (because 5 is prime and does not divide 288 exactly) So this requir...

Related Documents

Particularly Exam
Particularly Exam
Particularly Exam
Particularly Exam
Particularly Exam
Particularly Exam
Authenticates Notes
Authenticates Exam
Authenticates Exam
Infrastructure Notes
Particularly Notes
Traffic Generation Notes
Repudiation Notes
Repudiation Notes
Immediately Notes
Establishment Notes
155, "/var/app/current/tmp/"