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MIT's New 5-Atom Quantum Computer Could Make Today's Encryption Obsolete (pcworld.com)
An anonymous reader writes: In traditional computing, numbers are represented by either 0s or 1s, but quantum computing relies on atomic-scale units, or "quibits," that can be simultaneously 0 and 1 -- a state known as a superposition that's far more efficient. It typically takes about 12 qubits to factor the number 15, but researchers at MIT and the University of Innsbruck in Austria have found a way to pare that down to five qubits, each represented by a single atom, they said this week. Using laser pulses to keep the quantum system stable by holding the atoms in an ion trap, the new system promises scalability as well, as more atoms and lasers can be added to build a bigger and faster quantum computer able to factor much larger numbers. That, in turn, presents new risks for factorization-based methods such as RSA, used for protecting credit cards, state secrets and other confidential data. "If you are a nation state, you probably don't want to publicly store your secrets using encryption that relies on factoring as a hard-to-invert problem," said Chuang. "Because when these quantum computers start coming out, [adversaries will] be able to go back and unencrypt all those old secrets."
Way back in 1972, before many Slashdotters were even born, I remember hearing about how quantum computers were just "5 years away".
Then in 1977, I remember hearing about how quantum computers were just "5 years away".
Then in 1982, I remember hearing about how quantum computers were just "5 years away".
Then in 1987, I remember hearing about how quantum computers were just "5 years away".
Then in 1992, I remember hearing about how quantum computers were just "5 years away".
Then in 1997, I remember hearing about how quantum computers were just "5 years away".
Then in 2002, I remember hearing about how quantum computers were just "5 years away".
Then in 2007, I remember hearing about how quantum computers were just "5 years away".
Then in 2012, I remember hearing about how quantum computers were just "5 years away".
I have a strong suspicion that in 2017 I will be hearing about how quantum computers are just "5 years away".
I am still pretty convinced that the "quantum computer"-hype is based on fundamentally flawed assumptions, and that they won't break RSA (or other practical problems) of any reasonable size, that are not also easily solved with conventional computers.
Just because a model works with probabilities of "uncertain states" does not mean reality will reveal a "solution" based on all possible combinations of such states in no time. There is no compelling evidence yet that a quantum computer will find solutions quicker than it takes the real, physical hardware of that computer to take on all relevant input state combinations.
I'm prepared to bet the safety of my encrypted data on that, and I am convinced that 40 years from now, we'll look back at the hype around quantum computers the same way we today look back on the era of analog computers in the 1960s/1970s, when it was a plausible approach to solve some (back then hard-to-compute-digitally) equations, like for numerical calculus, by building physical systems (electronic circuits) that were known to behave in a way that equations could be solved by carefully adjusting some input voltages, then measuring some output voltage. We know that the precision achievable by such analog computers is very limited, and see the same problem preventing "quantum computers" from ever providing solutions that need to process a significant amount of information.
Surely they mean Decrypt, right? I mean, these are supposed to be the best and brightest, MIT "creme de la creme", right?
Isaac Chuang is professor of physics and professor of electrical engineering and computer science at MIT. He is NOT professor of English at MIT. So step the fuck off, Chris Boyd. And stop unnecessarily capitalizing your Ds.
The key will be scalability. Its an interesting experiment as it taps into the fundamentals of computing. It could however well be that the effort of keeping things disentangled grows exponentially (something which Shor's algorithm does not address). Like in dynamical systems theory, where computing the 10th iterate of f(x)=4x(1-x) with some initial condition like x=0.4 is no problem. It gives 0.297... already for a a hundred iterations the result become ambiguous and the answer becomes hardware and software dependent. No error correction can bypass these fundamental sensitive dependence of initial condition difficulty. So, it could well be that it is possible to factor a 10^10 digit number nicely but that things become more and more difficult larger numbers like integers with 100reds of digits and that RSA will remain save from quantum computer attacks. But who knows? The nice thing is that if it will be faster, one will be able to demonstrate it by factoring otherwise not yet factored numbers.
First, most encryption is not even really affected. For block-ciphers a working and large enough QC halves the key-length. AES-256 would still be perfectly secure and AES-128 would still be hard (but maybe possible) to break. And second, factoring RSA-2048 (which is regarded as too short today) would need around 2200 qbits to factor with this "breakthrough". They are at 5 qbits now. Where where they 10 years ago? Oh, right, at the same low number. If progress is made at this rate, they will be able to break RAS-2048 in x years, where x goes towards infinity, i.e. _never_.
This is about as valid as claiming the invention of paper threatens RSA, after all you can do attacks far faster with paper than with stone tablets.
Can we please stop the moronic and false "success" stories about quantum computing?
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Things that don't yet exist may make things that currently exist obsolete.
Shit happens when you post AC. If you won't own your comment and risk your reputation on it, then don't complain when it gets modded -1.
Human Rights, Article 12: Freedom from Interference with Privacy, Family, Home and Correspondence
Two things. First, exponential growth can't continue indefinitely. Second, once all the easy problems are solved, the ones left will require 90% of the total time. We have the lessons of AI and fundamental physics, where all the "easy" problems were solved decades ago, both disciplines becoming pretty stagnant since. Ergo, for all we know, the world 100 years from now might not look all that different.