In room-size metal boxes, secure against electromagnetic leaks, the National Security Agency is racing to build a computer that could break nearly every kind of encryption used to protect banking, medical, business and government records around the world.
According to documents provided by former NSA contractor Edward Snowden, the effort to build “a cryptologically useful quantum computer” — a machine exponentially faster than classical computers — is part of a $79.7 million research program titled, “Penetrating Hard Targets.” Much of the work is hosted under classified contracts at a laboratory in College Park.
With such technology, all forms of public key encryption would be broken, including those used on many secure Web sites as well as the type used to protect state secrets.
The basic principle underlying quantum computing is known as “quantum superposition,” the idea that an object simultaneously exists in all states. A classical computer uses binary bits, which are either zeroes or ones. A quantum computer uses quantum bits, or qubits, which are simultaneously zero and one.
While a classical computer, however fast, must do one calculation at a time, a quantum computer can sometimes home in on the correct answer much more efficiently, without running those calculations.
A working quantum computer would open the door to easily breaking the strongest encryption tools in use today, including a standard known as RSA, named for the initials of its creators. RSA scrambles communications, making them unreadable to anyone but the intended recipient, without requiring the use of a shared password. It is commonly used in Web browsers to secure financial transactions and in encrypted e-mails. RSA is used because of the difficulty of factoring the product of two large prime numbers. Breaking the encryption involves finding those two numbers. This cannot be done in a reasonable amount of time on a classical computer.
A description of the “Penetrating Hard Targets” project. Another project, called the “Owning the Net,” is using quantum research to support the creation of new quantum-based attacks on encryptions like RSA.
This document describes classification levels of information related to the NSA’s quantum computing efforts.