Chances are that you’re familiar with the National Security Agency as the U.S. government organization that listens in on foreign communications and cracks their encrypted messages for useful intelligence.
While foreign communications surveillance is agency’s main purpose, no everyone knows that it’s also heavily involved with protecting sensitive government communications from interception and decryption by foreign intelligence agencies.
This means the NSA is deeply involved in developing encryption standards that are as uncrackable as possible. But not just uncrackable now, the encryption standards have to withstand the test of time and remain uncrackable long into the future. That test of time can include developing cryptography that can defeat the potential massive power of a large quantum computer, even though nothing of that sort currently exists.
“A lot of classified data has a long lifetime,” said Neal Ziring, NSA Capabilities Technical Director. He said that this is because it’s in hardware that takes a long time to get into the field and that once put into service, lasts a long time. Such items may include Navy ships (which remain in service for decades) or spacecraft (which can be in service even longer).
Because the data the government uses can last a very long time, the NSA is already working on ways to protect the data against capabilities that currently exist only in a very limited form. Such a capability is quantum computing, which might be limited today, but promises to be a critical technology in the decades to come.
Ziring said that for commercial users that don’t necessarily have to consider such long timeframes, it’s still worth preparing for post-quantum security because the industry and the markets are heading in that direction. He said standards bodies that certify encryption are working on such standards and that the industry needs to be ready to implement encryption that can withstand assaults by quantum computers when the capability arrives.
The reason that the NSA and other security and encryption researchers worry about quantum computing isn’t just because it can result in very fast computers. It’s because such computers can run complex algorithms that can’t be used efficiently using classical digital computers. That’s because quantum computers can use quantum superposition.
A qubit, or a quantum bit, is a quantum unit of information which can have many positions between the normal states of 0 and 1, and in fact can occupy all of those states at the same time. This means that a qubit can encode an infinite amount of information, at least until the state of the qubit is observed at which point it collapses into a single state.
If the qubit is paired with another so that it’s entangled, then the other qubit will always have the same state. These properties enable the use of quantum algorithms that could never be executed in a classical computer.
As you can see, quantum computers have capabilities that are simply unavailable to classical computers, and it explains why all of the brute-force computing in the world can never bring to bear the computing power that is available from quantum computer. This is also why the NSA is less worried about massive computing power than it is about the special capabilities of quantum computers.
This concern has led the agency to start researching quantum resistant encryption algorithms. In the process, the NSA has developed a list of current encryption techniques that should no longer be used, including SHA-256 and AES-128. This list is in the NSA’s FAQ for the Commercial National Security Algorithm Suite and Quantum Computing.
Also in that FAQ is the list of encryption methods that are recommended for national security systems. Commercial users that aren’t working with classified information aren’t required to use those stronger encryption methods, but they are certainly allowed to and by doing so they will be ready for future encryption practices.
The next issue for commercial encryption users is how to make sure that their encryption practices meet the NSA’s guidelines, especially if they’re handling information that needs to be protected, which may include some types of financial, medical or personal information. The answer is to make sure that the encryption complies with the requirements of FIPS 140-2 (federal information processing standard).
There are also a number of encryption providers that meet FIPS 140-2 or similar standards recognized by the National Institute of Standards and Technology.
However, just having good encryption isn’t enough. “It’s important to have good algorithms, properly implemented and keyed,” Ziring said. “They should use certified cryptography. It’s very important that implementations be certified as meeting FIPS 140.”
If your organization is part of the National Security System, then the NSA may be able to help you make sure you’re using the proper implementation and key management. But there are other ways that the NSA can provide help. For example, companies that are part of the U.S. critical infrastructure can ask the Department of Homeland Security for help, and the DHS can ask the NSA for help.
Likewise, organizations needing help with their financial systems can work with the Treasury Department to make sure that they’re meeting standards and Treasury can get help from the NSA.
But the real importance is that any solution has to be more than just good encryption, it also needs the proper implementation and proper key management policies..