IBM Warns Quantum Computing Will Break Encryption (zdnet.com)

Long-time Slashdot reader CrtxReavr shares a report from ZDNet: Quantum computers will be able to instantly break the encryption of sensitive data protected by today's strongest security, warns the head of IBM Research. This could happen in a little more than five years because of advances in quantum computer technologies. "Anyone that wants to make sure that their data is protected for longer than 10 years should move to alternate forms of encryption now," said Arvind Krishna, director of IBM Research... Quantum computers can solve some types of problems near-instantaneously compared with billions of years of processing using conventional computers... Advances in novel materials and in low-temperature physics have led to many breakthroughs in the quantum computing field in recent years, and large commercial quantum computer systems will soon be viable and available within five years...

In addition to solving tough computing problems, quantum computers could save huge amounts of energy, as server farms proliferate and applications such as bitcoin grow in their compute needs. Each computation takes just a few watts, yet it could take several server farms to accomplish if it were run on conventional systems.
The original submission raises another possibility. "What I wonder is, if encryption can be 'instantly broken,' does this also mean that remaining crypto-coins can be instantly discovered?"

Comments

crypto-coins?

[DogDude]

What I wonder is, if encryption can be 'instantly broken,' does this also mean that remaining crypto-coins can be instantly discovered?

This could theoretically be the biggest breakthrough in computing since transistors, and this person is wondering about how it's going to affect Monopoly money? Jesus.

Re:crypto-coins?

[ledow]

Hashes are actually one of the best ways to stay QC-safe.

At the moment, we use our existing encryption algorithms to generate hashes. Instead, most of the quantum-safe encryption algorithms use hashes to build themselves.

The reason is quite simple if I can use an analogy. It's not 100% accurate, but good enough to make most people understand.

First - a hash.
You take an input, you generate a "mini-mash" of it - you jumble it up and cut bits out in a predictable manner until you get something that is absolutely tiny but built from that original input.

The same input will give the same hash every time, because you do the same thing every time. Yet millions of different inputs might give you that same mini-mash (because they are much fewer hashes than there are data-sets, so by chance they overlap sometimes - a hash collision) but that hardly matters in real life because the chances of those other inputs being valid Microsoft Word files, or containing the same secrets as your files are infinitesimally small.

Quantum-computers attacking conventional encryption works like this:
- you "build a circuit" that performs the same encryption that was used (e.g. AES, ECC, etc.).
- you plug in the ANSWER (the encrypted text) into the end of it.
- by some magic of physics, it instantaneously determines the only possible inputs that could have ever formed that answer. Thus, it works out the SECRET INPUT (i.e. the keys) that was originally used to encrypt it - all in one "tick".

As such, QC defeats traditional encryption entirely. Every encrypted text/web session is one tick away from compromise with zero effort required and only tiny amounts of time expended.

But when you apply that technique to hashes, there may not be only one possible input. In fact there may be an infinity of inputs that give the same hash (because the input can be any size, right? So the mini-mash of a entire novel could the same as the mini-mash of "123" or the same as the mini-mash of a dataset as large as the universe).

As such, the QC can't determine the answer - it gets all the answers and doesn't know which one's right. To know which one was right, you'd have to check them all... and you're now back from "working out the answer instantaneously" to "checking all the possible combinations one at a time".

So instead you can build QC-safe encryption by using hashes upon hashes upon hashes upon hashes. Now any possible inputs a quantum computer may determine is lost in an infinity of other inputs... and it's no longer as simple as "just give us the only input that looks like a Word file" - you have to check them all.

As such, hashes are the basis of much more security, based on their "unknown but potentially infinite amount of data" turned into "a small set of characters" property.
  Crypto-currencies use hashes a lot (Bitcoin is/was basically built upon "keep hashing different things on the end of this string until you get a hash of 0 out of it") and so may be the last thing to fall to QC.

In the same way that QC turns cryptanalysis on its head, to solve the problem of QC we turn hashes and encryption on their heads.

Re:crypto-coins?

[ZorinLynx]

With the rate that crypto-currency mining is wasting energy, breaking blockchain might be a very good thing for our future.

Re:crypto-coins?

[thegarbz]

It might break blockchain, yes, but, like, who cares?

I care. The sooner we can break blockchain the sooner we can stop the insane amount of wasted energy we are pouring into this retarded tulip and go back to reducing the world's energy consumption like we were doing before this stupidity infected us.

Both

[dilvish_the_damned]

The original submission raises another possibility. "What I wonder is, if encryption can be 'instantly broken,' does this also mean that remaining crypto-coins can be instantly discovered?"

Yes and No.