Cryptography Reference
In-Depth Information
(a) What is
non-secret encryption
?
(b) Who was Britain's equivalent of Rivest, Shamir and Adleman and when did
he come up with his idea?
(c) Why were these ideas not published?
16
. Quantum computers will have a significant impact on the practice of crypto-
graphy.
(a) What is the likely impact on public-key cryptography if a practical quantum
computer can be built?
(b) How fast can an exhaustive key search be conducted on a quantum
computer?
(c) What is the likely impact on symmetric cryptography if a practical quantum
computer can be built?
17
. There have been various side-channel attacks against public-key crypto-
systems.
(a) Provide a short description of one such attack.
(b) Why do you think public-key cryptosystems are particularly vulnerable to
certain types of side-channel attack?
18
. Public-key cryptography normally works under the assumption that public keys
are, as defined, public pieces of information. However, some people have
suggested that, in certain circumstances, it might make sense to keep public
keys secret. This means that only those who
need
to know a public key are
given it by some secure means, and they are required to store the public key as
a secret.
(a) What are the potential costs and benefits of using
secret
public keys?
(b) Can you think of any applications where this idea might have some value?
