Name:
State all assumptions necessary to answer the questions.
CS 585 Final
May 4, 2005
Suppose you are given a function f that maps short integers (2 byte) to 8 bit ASCII characters. You are told
that the function has the strong collision property, and that you are to use it for a digital signature. Explain
why or why not the strong collision property is useful for this purpose.
Why is it important to use prime numbers for generating the keys in RSA?
Consider users A and B, and the RSA public key (e, n) and private key d. Suppose that both A and B
(and only A and B) had both keys and that to communicate they would encrypt using the private key and
decrypt with the public key. Why or why not is this still an asymmetric cipher? What other considerations
are there if RSA is used in this manner?
