The complementary part of the picture is the NSA’s effort in quantum cryptography, which provides new security methods that are resistant even to quantum computers or any other kind of code-breaking. It’s quite likely that a quantum computer will be built eventually, but quantum mechanics can make codes as well as break them. Numbers up to four, not exactly the “large numbers” we were talking about earlier. Remember, the NSA’s current program, if successful, will handle
No one has built a practical quantum computer that could break RSA, and that goal is still a long way off - decades, at the current rate of progress. Translating Shor’s algorithm into practice is tremendously difficult. However, you needn’t worry about your bank account. Making the numbers a little bigger makes the problem much harder – it “scales exponentially”!Ī microchip for trapping atomic ions which could be the heart of a future quantum computer. This would take an exceedingly long time since you would have to perform many multiplications. You would just have to try factors, almost at random, until you hit on the correct factors by chance (547 and 617). In our example, you are given the number 337,499 and asked to find out which numbers (the “factors”) should be multiplied together to produce 337,499. However, suppose someone just gives you a large number and asks you to work the process in reverse. In the jargon of computer science, the problem “scales polynomially”. There’s a simple process that you can follow and making the numbers a little bigger only makes the process take a little longer.
Multiplying two large prime numbers is easy – say, 547 × 617 = 337,499. The Rivest-Shamir-Adleman (RSA) algorithm, which protects almost all e-commerce, relies on one fact that can be understood with primary-school maths (it can even be used to send love letters). Modern cryptography is, in many ways, a branch of applied mathematics. Basic maths and cryptographyīut iIt’s no accident that our NSA funding managers looked like mathematicians. I was a little disappointed until I came up with a theory that when they went back to the NSA building, they would tear off the sweaters to reveal the long trenchcoats of a typical spy drama. They looked like my maths professors from undergraduate days – slightly nerdy men in sweaters. One day, our funding managers came to visit. In fact, my own PhD work on quantum computing with trapped ions was largely funded by the NSA. The NSA has been financially supporting non-classified quantum computing research at universities since the 1990s, and many academic journal articles acknowledge NSA support.
0 kommentar(er)
