## Exam Information

Login / Sign Up to View Document

## 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 = 17·19. 17 and 19 are primes. So this holds.
Second requirement [4 points]
Recall that if n =p·q 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

© Copyright 2020 , Koofers, Inc. All rights reserved.

The information provided on this site is protected by U.S. and International copyright law, and other applicable intellectual property laws, including laws covering data access and data compilations. This information is provided exclusively for the personal and academic use of students, instructors and other university personnel. Use of this information for any commercial purpose, or by any commercial entity, is expressly prohibited. This information may not, under any circumstances, be copied, modified, reused, or incorporated into any derivative works or compilations, without the prior written approval of Koofers, Inc.