"PKI stands for Public Key Infrastructure. In the broad
sense of the term, it refers to an infrastructure that allows
differents parties to interact using public key cryptography (this
definition could apply to PGP keyrings the). The 'term' PKI is now
almost synonymous with PKIX which is an IETF standard for a more
hierarchical PKI. The PKIX trust model is a lot more formal than
the one in PGP and therefore fits much better the corporate
world."
"It has not been immediately clear that a quantum
computer offers really special advantage until the work of Simon
and Shor shows that such a machine could factorise natural number n
in polynomial time. Note the algorithm has been recently
implemented (NATURE december 2001) and tested on the number 15 (!).
Nobody knows a classical algorithm capable of such
time-polynomial factorisation, and this has been a real shock for
the computing people. Grover showed also how to search an
unstructured database more rapidly. Such quantum machine can
generate truly random oracle. To sum up it seems that quantum
computer could execute much more quickly some computation and
provide new sort of resource.
Feynman also foresees that such computer would be able to
simulate efficiently quantum phenomena. There are good reason (but
still no proof) that quantum phenomena cannot be simulate
efficiently on a classical computer. Since then we get surprising
results every month in quantum communication, quantum information,
quantum computing, but also quantum games and strategies. The
number of publications grow in all countries."
