Encryption techniques developed to keep data secure could soon be a thing of the past, following the development of a new quantum computer using just five atoms. A new device is the first to ever realize a potential mathematical technique developed more than 20 years ago.
Massachusetts Institute of Technology (MIT) researchers devised the new system, which utilizes an ion trap to control the atoms. Laser pulses are used to carry out Shor's algorithm to determine the prime factors of the number 15 — five and three. This process could be scaled up to factor larger numbers, researchers speculate.
Using hundreds of contemporary computers, investigators were able to factor a number with 232 digits, but the process took two years to complete with current technology. Factoring large numbers is a challenge using current computer systems.
This "factoring problem" is the basis of most of today's encryption schemes used by banks, corporations and governments to protect sensitive data.
Quantum computers using hundreds of atoms in a larger version of the MIT design could factor numbers quickly, potentially ending the ability of encryption to secure data. An algorithm to calculate the factors of large numbers was designed in 1994 by Peter Shor of MIT. However, investigators have been unable to successfully build a device to carry out the process.
"We show that Shor's algorithm, the most complex quantum algorithm known to date, is realizable in a way where, yes, all you have to do is go in the lab, apply more technology, and you should be able to make a bigger quantum computer," said Isaac Chuang of MIT.
Digital computers rely on just two numbers — zero and one — to complete their calculations. Quantum computers utilize qubits — numbers that superimpose zero and one in a single place. This allows processors to carry out more than one calculation at a time, greatly increasing speed and efficiency over current technology. Normally, it takes 12 qubits to factor the number 15, but the new technique developed at MIT reduces that by over a half.
As the process is scaled up, the devices would require additional atoms, as well as lasers. This means such machines would be large and pricey — at least for the time being.
Development of the new five-atom quantum computer was detailed in the journal Science.