"Ian Watson - Caucus Winter" - читать интересную книгу автора (Watson Ian)

Ah, but I had nothing to do with protecting the President or visiting
dignitaries. The Secret Service is part of the Treasury Department. So we are
equally keen on safeguarding our currency from counterfeiters and such.

"...I'm part of the computer crime division."

"Today's money crimes are computer crimes," Outi told the drunk, as if he was a
child and she was his teacher. "Swindling banks electronically."

I tried to stand up, but somehow I was still sitting down. Making a stronger
effort, I visited the toilet.

On my return, another beer awaited me, and Outi was explaining to our uninvited
guest, still in English, about encryption. All the guys from Nokia loved talking
English to each other. Practice isn't the right word. They spoke English almost
better than I did myself. Anyhow, the drunk was fairly bewildered -- which was
part of the fun -- but he must have caught some of the drift, because he mumbled
about code books and magic ink.

Outi shook her head. "No, no! Nowadays data is encrypted by multiplying two big
prime numbers together. That's easy for a computer to do. You end up with a
number 129 digits long, say. But to factorize that long number -- to find which
two prime numbers were multiplied -- takes even the best computer months and
months. That's because it has to try out all the possible combinations one after
another."

"One after another," echoed our inebriated friend. He waggled both index fingers
as if carrying out a sobriety test.

"So all financial and military and government data is safe -- until the quantum
computer comes along."

Oops, Outi wasn't going to attempt to explain a quantum computer to a drunk with
a modest grasp of English? Just then, I hardly felt competent to do so myself.
Outi was one for a challenge. She became a bit incoherent, but it was still a
virtuoso performance.

Basically, the fundamentals of the universe aren't solid objects; they

are probabilities. Wave functions. An electron "exists" as a mixture of possible
states until you make a measurement, whereupon the wave function "collapses"
and, bingo, there's one reality -- and the electron is in such-and-such a state.
However, this implies an alternative reality where the electron did something
else. Consequently, there's a cloud of alternative ghost-worlds, as it were.
Build a computer that uses these principles, and it will be able to carry out
its computations simultaneously in a host of multiple realities. Wrong solutions
that don't "interfere constructively" will simply cancel out. Your quantum
computer will be able to factorize that 129-digit number in a few minutes
instead of months.