The NSA project came to light in documents passed to the Washington Post by former NSA contractor Edward Snowden.
The agency hopes to harness the special qualities of quantum computers to speed up its code-cracking efforts.
The NSA is believed to have spent about $80 million on the project but it has yet to produce a working machine.
If the NSA managed to develop a working quantum computer it would be put to work breaking encryption systems used online and by foreign governments to keep official messages secure, suggest the documents excerpted in the Post.
The quantum computer is being developed under a research program called Penetrating Hard Targets and is believed to be conducted out of a lab in Maryland.
Many research groups around the world are pursuing the goal of creating a working quantum computer but those developed so far have not been able to run the algorithms required to break contemporary encryption systems.
Current computers attempt to crack encryption via many different means but they are limited to generating possible keys to unscramble data one at a time. Using big computers can speed this up but the huge numbers used as keys to lock away data limits the usefulness of this approach.
By contrast, quantum computers exploit properties of matter that, under certain conditions, mean the machine can carry out lots and lots of calculations simultaneously. This makes it practical to try all the possible keys protecting a particular message or stream of data.
The hard part of creating a working quantum computer is keeping enough of its constituent computational elements, called qubits, stable so they can interact and be put to useful work.
The NSA is not believed to have made significant breakthroughs in its work that would put it ahead of research efforts elsewhere in the US and Europe. However, the documents passed to the Post by Edward Snowden suggest the NSA’s researchers are having some success developing the basic building blocks for the machine.
mSLXf2UclKEImage source: Wikimedia Commons President-elect Donald Trump celebrated his election victory at the Ultimate Fighting…
Millions of voters across the US chose to return Donald Trump to the White House…
Donald Trump declares victory in the US election as he addresses jubilant supporters in Florida.…
Stocks around the world are rising as Donald Trump appears to be on the cusp…
Donald Trump has won Pennsylvania, North Carolina and Georgia and taken a lead over Kamala…
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…