Cryptography Reference
In-Depth Information
11
.
It is possible that an application using symmetric encryption might also require
non-repudiation based on a digital signature scheme. Compare different ways
of combining these two cryptographic primitives.
12
.
In Section 7.4.3 we discussed a range of issues in which digital signatures and
handwritten signatures differ. Prepare a two-minute summary of this discussion
for your linemanager which outlines the differences that you regard as themost
fundamental.
13
. Determine the extent to which digital (electronic) signatures are currently
supported by the laws that apply to the country in which you currently reside.
14
. Bob has successfully verified a digital signature that appears to come fromAlice.
However, Alice is convinced that she did not create this digital signature. What
'defence' arguments could Alice use in her denial of the digital signature?
15
. There have been many digital signatures proposed with additional properties.
One of these is
blind signatures
.
(a) What is a blind signature?
(b) Provide a physical world analogy for a blind signature.
(c) What potential applications are there for blind signatures?
(d) Describe one method of producing blind signatures that is based on RSA.
