ECE 646, Midterm Exam 2
Fall 2000
Multiple-choice test
1. (1 pt) Standard techniques used for padding of the RSA messages in
signatures with appendix include
A. ISO 9796
B. PKCS #1 (ver. 1.5) for encryption
C. ISO-14888
D. OAEP
E. PKCS #1 (ver. 1.5) for signatures
2. (1 pt) Using OAEP (Optimal Asymmetric Encryption Padding) before the
RSA encryption protects against the following attacks:
A. superencryption attack
B. encrypting a set of most likely messages with the public key, and
comparing the result with the ciphertext
C. factoring the modulus N using the General Number Field Sieve Method
D. short message attack (e=3, M<N1/3)
E. factoring the modulus N using Pollard's p-1 method
3. (1.5 pt) Match each RSA modulus N with the most efficient currently
known method of factoring a number of the given form and size:
A. N=P⋅Q, where P - 25 decimal digit prime, Q - 275 decimal digit prime
B. N=P⋅Q, where P - 50 decimal digit prime, Q - 50 decimal digit prime
C. N=P⋅Q, where P = 2521-1, Q - 50 decimal digit prime
D. N=P⋅Q, where P - 50 decimal digit prime, Q - 100 - decimal digit prime
E. N=P⋅Q, where P = 2512+1, Q - 50 decimal digit prime
a. GNFS - General Number Field Sieve
b. QS - Quadratic Sieve
c. Pollard's P-1 method
d. ECM - Elliptic Curve Method
e. Cyclotomic Polynomial Method
