Google, NASA: Our quantum computer is 100 million times fast

[James C]

Google, NASA: Our quantum computer is 100 million times faster than normal PC

http://arstechnica.com/information-tech ... normal-pc/

At an event yesterday at the NASA Ames Research Center, where the D-Wave computer is kept, Google and NASA announced their latest findings—and for highly specialised workloads, quantum annealing does appear to offer a truly sensational performance boost. For an optimisation problem involving 945 binary variables, the D-Wave X2 is up to 100 million times faster (108) than the same problem running on a single-core classical (conventional) computer.

[Scooby]

My first thought was there goes encryption to h***

But I read the article and comments it seems we are still OK

from the comments...

Well a couple things. First is that DWAVE is a quantum annealer. It is
utterly useless for breaking crypto. General purpose quantum computers
capable of implementing Shor's algorithm are at this point academic
experiments. I think the best experiments were on the order of 5 qubits
(i.e. can factor 5 bits numbers yes like "21"). Now DWAVE is pretty cool
stuff and almost magic for the very limited set of problems it is optimized
for but it isn't well suited for breaking crypto.

The second is most cryptography can't be broken by quantum computing.
Shor's algorithm doesn't work against symmetric ciphers or hashing
algorithms. Grover's algorithm can be used but the speedup is rather
lackluster. You can achieve the same security by just doubling the
key/hash length.

Also while most asymmetric encryption is highly vulnerable to Shor's
algorithm running on a sufficiently sized general purpose QC (that don't
exist yet) there are "post-quantum" algorithms which are not. They are
not widely used today because they tend to have keys much larger and
are significantly slower but they provide a quantum resistant option.

No crypto is vulnerable to quantum annealers (at least there is no current
algorithm which would enable a quantum annealer to attack a classic
cryptographic system). ECC like all classical asymmetric cryptography can
potentially be broken using Shor's algorithm under some as of yet
hypothetical very very large general purpose quantum computer. IIRC
from a paper I read years ago it is roughly the same as RSA in this
respect. The big problem with that is RSA and ECC represent essentially
all asymmetric cryptography being used today and both are equally
vulnerable to future quantum computers.

A good read is also

http://www.scottaaronson.com/blog/?p=2555

from the comments...

The D-Wave has not shown an asymptotic improvement (yet) over the
best classical algorithm, even for an artificially-constructed problem
designed to best highlight such a difference.

[gcmartin]

There is a MAJOR difference in the instruction sets and workload structures in Quantum computing. It will take many-many-many QCs to do what is achieved by General workload computers since 1960s. As such same is similar for QCs to do what Scientific computers (like Crays, etc.) do.

But, as mankind continues to move forward, our ability to integrate all of these into a "mankind system" is possible. At some point in the distant future, it will become necessary.

[bigpup]

It will get faster as soon as they discover Puppy