I'm happy to
be here. They asked me if it was
my first time speaking I said
yes and no from sky talks was a
smaller room so happy to see so
many people. So talking about
quantum computer.
How do youknow how
quantum works or quantum
-- so this is very basic
that you have to know.
Complex number -- obviously
so if you
don't know these please leave
the room. I'm kidding. The nice
thing I will say that you don't
need to get this stuff to
understanding quantum computing
-- lost audio -- I will try to
convince you that. Outline, I
will be talking very broad but I
will not go into technical
details so how things work and I
will give you the ideas and
applications. Very brief crash
course of quantum computing. So
based on quantum mechanisms
about you see the operating
system of nature on nature like
the framework on top which the
gravity -- nuclear forces are
running so you get series in --
and you try to adapt them to do
quantum mechanics. There is my
only side about quantum
mechanics. What it says that the
particles in the universe like
electrons and protons they
behave randomly but not not
inception they are not
predictable. But you have no way
to predict what is going to
happen but what is different
compared to what the randomness
can be negative this is problem
but negative and complex
numbers. So that seems to be
counter intuitive and you have
to trust me that it does make
sense mathematically. So --
(lost audio) -- so when you have
not looked as the Q bit it is in
the state that if you observe
the Q bit and ask what is value
it is zero with property and
some other property.
Coefficients and -- of the
straight line and the bracket is
called the bracket notation you
don't need to remember this but
what you need to know that is
alpha and beta used called -- so
they can be a negative or
complex and the property so you
take this value and square it
and that property that is what
you get so a number between zero
and one. You have different
properties for each byte.
Sequence of eight quantum bytes
maybe it will be 0X or 00 and so
on. And using these objects like
quantum computer you have
registered which can we --
anything you want and you will
transform the state so that is
how you will compute. You will
have kind of quantum assembly
but you have will different
restrictions. The importance to
remember that will be reversible
but can go back in the past so
for your information you don't
have classical assembly you have
end operation register one or
two and then you register one
and you can't go back in the
past not the previous value and
here you have what you modify so
quantum objects about you just
chain the properties what you
learned in high school in
algebra so just do
multiplication and transfer the
property and when you properties
go to one you want -- sum to one
as well. I will not go more
technical but that is idea
remember that quantum computing
is multiple together some
properties of complex. And that
is it. So you have this set of
register that can be bot on the
same time and at the end you
observe one bit or more and that
your result. And the importance
thing is that you cannot
simulate this using quantum
computer say you have a quantum
byte it is encoded 256 different
properties so you might be able
to start this on the normal
computer but now say you have a
quantum motor of two bits. How
do you start this classically
might be doable but if you have
64 bits cannot start this on the
classic computer. So can try
this online there are some
simulators you cannot go too
far. Multiple vision for all of
this was to simulate quantum
physics and for some reason that
you cannot simulate the quantum
computer -- so a friend of said
okay to simulate this we need to
simulate a quantum computer and
to understand how physics or
nature works by submitting all
the quantum phenomenon. I will
just go through to common
misunderstanding about this and
people say quantum computer that
is super faster and way faster
and solves problems but bad news
doesn't solve all the problems.
I don't know if it is familiar
to you -- where you list of
cities and you have to find the
best route. All have problems
have some structure that makes
them difficult and practically
impossible to solve on a normal
computer. You will not solve
these hard problems on the
computer. The good news is you
do have quantum speed up for
some specifications making the
impossible possible on the
quantum computer and going from
N to P times Q is difficult on
the normal computer but easy on
the quantum computer so the
application is -- I will talk
about this later. So the last
caveat is some people say you
have the super notion trying
everything the person for free
-- that is not the idea, the
idea is in some sense several
values of the same time but you
can only look at one result but
like all of this is useless and
you cannot say I want to look at
result that gives this value.
You look at the random results
so no magic here. So that was it
for the tear. Let's move to
practical part. Like I said --
we know how to factor 15. Three
times five. We also know how to
factor 153 and 56,123. But that
is caveat here for these numbers
they use special -- about in
some sense they have to know in
advance what was the solution
before searching for the
solution. I want to say that we
have very far from the use
application of quantum computer
and the reason is it is
difficult to build. First of all
you is have to find a object to
simulate your Q bit so you will
take some physical particle and
sometimes foreign molecules --
the main problems they are
facing in quantum computer is
that what is -- interact with
the rest of the system and this
will complicate the system --
you can correct all your -- in
time but in practice much more
difficult. You have to computer
temperature plus absolute zero.
And we don't know how to scale
to several hundreds or thousands
of Q bits so we have to result
four or 5Q bits but if you want
to break all the crypts in the
world you need a thousand and we
are far from this. 9Q bits this
year not a actual quantum
computer just a set of 9Q bit
that's can live together for a
few seconds while correcting --
in the environment. Lost audio
-- I don't think they do. They
probably don't but -- so like I
said -- RSA -- explain why RSA
this is based on factoring
numbers. If you can factor
numbers then you can break RSA
and then factor numbers so it is
hard with computer we don't have
a math proof of this but we
convinced that is our problem.
Factoring is not complete but
easy on the quantum computer.
Doing a quantum for transform
and gives you the result. And
what is nice within is not
specific for factoring, it is
for a whole class of problems
that we call the -- fighting a
subgroup ribosome bigger group
and turns out that the disc
algorithm is another time of
this problem. So the problem
behind the -- problem is you
have number G and you know a G
to power of Y and you don't know
why so you look for Y. You can
try it. It's not easy if you do
it only big numbers. And again,
it easy on the quantum computer.
So what about -- or has
functions. A little bit faster
than is quantum computer but not
that faster just that is search
for the key would be much
faster. So you get half of 64
bits of security. If you do some
advance math if I want 120 bit
security I need a key off to 56
and we have version of 256 and
we not have -- of 12 bits and
the reason behind this -- we can
search in a table of elements in
time square with N instead of M.
So if you have two to the N --
so there is a field called post
quantum crypting to fee and goal
is the find alternatives. Lost
audio -- means equations with
many variables and the variables
are come fined in such a way
with multiplication and once you
have that much much harder to
solve. You do multiplication it
is harder so impossible. But if
you want the use it, most of
time you need the have a shorter
system. You need to have some
trace structure and that reason
why some -- working I don't --
now something important to
understand, someone has quantum
computer that created it might
break -- you can still
signatures but issuing knew ones
with a quantum system. But if
you encrypt something with a
nonquantum safe cipher it is too
late and going to be encrypted
and no use to encrypt again. So
the bottom line here is more
important the have quantum
encryption you can still wait
until the quantum computer is
created. So two types of
encryption techniques so nothing
new. Ideas from 70s or 80s. We
have very large keys kilo bytes
but today we have tera byte but
maybe kilo bytes not big data.
And the other one is -- very
simple to understand you have
function and you don't know the
function you know what it looks
like and you want to learn the
function. So you cannot guess
how it works. So fifth part is
quantum distribution. Here the
problem is like a quantum --
instead of using -- you use
physical phenomenon. Not really
quantum computing but using
quantum mechanics. The argument
is that if you are in the middle
you can't do the middle because
it will be detected by the law
of physics. It will be modified
so you will see the modification
you cannot copy quantum bits.
And are random. So this one is
the -- BB8 h invited by the guys
in 1984. This is simple. They
want -- so likes a few bits and
she has to select encoding. Here
it means just position of the --
you can see just simple
encoding. So she says blue-green
green and she will send this to
bob and he doesn't know the
encoding and thing is if you
have the same encoding you will
observe the right value and if
you don't have the -- it will be
too late to correct because once
you observe it, it is not a
quantum bit. So bob he observes
the bits that he receives and
then he publishing encoding and
Alice says you have the right or
wrong one and it just pick the
bits why you have same -- so the
scheme is more complicated but
that is general idea. But it is
not as secure as it pretends to
be. The first one is it is
quantum when you use the keys
when you store it in your system
you use classical -- so the
people say classical -- yes, but
then what do you do, you have to
use classical crypt. In practice
you to -- quantum hacking and
broke some of the first systems.
You can do this over the
internet and dedicated optical
fiber links so point to point
and limited in distance less
than a hundred km. You can put
repeaters or make -- now it is a
bit annoying. So that
application is quantum computer
if you wonder why I put this
here. I don't know if you
recognize this guy. Leverage the
no claim principle. The idea is
simple. The idea is when you
have quantum bits you can know
like momentum but you know bot
at the same time. You cannot
know everything about the
quantum object so if you don't
know everything you cannot copy
it. You cannot copy what you
don't know. In physics you have
this -- that cannot clone a
physical object to exact copy.
So you see the relation with
quantum cash. You will put some
Q bits on your bank note and so
only the bank can create the
ones. So that is suggest a
experiment and not practical
because it is difficult to put Q
bits on the note and to deal
currency problem. So you will
never see this for real but you
can imagine. You can imagine
software -- so using this idea
of quantum non-cloning, so you
have function here in green the
-- let's say you find you get
the code of function and maybe
sophisticated but you can
reverse the code. You check the
hash, if a strong hash you not
find the password easily. And if
you have binary you can copy the
bytes. So here is idea of
prediction that you cannot copy
the program. You have the
problem which is a list of Q
bits and you have no idea about
what the program is doing. So
like quantum cash it is not
something that will happen for
real. So my last one is about
learning. Seems to be hot these
days. I have seen some very good
talks and not so nice talks. So
one slide difficult to summarize
but see the science of getting
computer -- it is either
learning patterns or -- notion
of supervised -- un-supervised
like discovering patterns and it
is quite a success and feels
like for detection -- usually
better at finding similarities
that no monies and intern
detection for example we went to
find monies for specific notion
of no money. But security --
lots of false positive the
mission learning. Recommend
something that you don't want
the see it is not a big deal but
if you -- system or detects too
much you have a problem. Some
companies claim the use it but
sometimes just say we will use
mission learning just to say
they use mission learning. I
have not seen detail about this
so I don't think it works as
claim. Some people have been
trying to -- mission learning.
But a bit boring because not a
brand new algorithm, just take
the algorithm and run them on
your quantum computer. Things
like clustering. There are two
advantages and one sometimes you
have search in the big list of
data, so you can use what was
seen before to speed up the
search and you have the square
root improvement. You do get a
exponential speed up which means
it is something you could not do
on classical computer but you
need a quantum ram. So the idea
is out there. You give a address
and get the value add this
address so in quantum memory --
and you receive the values at
these addresses in
superposition. I have no idea
how the implement this and
physicist have no ideas. And the
idea of quantum learning -- so
if you have a quantitative you
don't have quantum -- so will be
useless. So time to conclude?
Maybe you were not happy about
this and you will be leaving the
room. It sucks. Doesn't even
solve problems. So -- this is an
article but if you are more opt
mystic person you will see it
differently. Stuff collecting
all the -- if you are math --
transforming a physical state.
You can take this microphone a
bunch of atoms you can see the
wall is big quantum computer
allowing da. What is universe
computing. So what some
physicist say we don't know if
it is possible to have a quantum
mechanics but if we have proof
that is poses then it will tell
us about physics. So even if we
fail we win something. So I hope
you liked this. If you have
questions, I will put the slides
at line. I have just been
interested in this stuff for
years and years. So if you want
to build a quantum computer
don't talk to me. Yeah. I have a
few minutes left. When I did
this talk people ask me why
don't you talk about the company
that is selling a computer. This
is recorded. So the company
selling the quantum computer, it
is a different type and it
cannot factor big numbers. So
that's it. Thank you for you
attention and I am happy the
00:32:18.303,00:00:00.000
take questions.
