In his book Codebreakers, David Kahn explains in fascinating detail the arms race that has taken place in the world of code-making and -breaking since the dawn of humanity. As cryptographers make scientific breakthroughs and build more sophisticated methods of obscuring and transmitting sensitive information, codebreakers work furiously to crack those systems. Even when one gains the upper hand temporarily, it's only a matter of time before the other overturns it. This cycle of ciphering and deciphering once seemed endless (and not a little frightening.)
However, today the technology known as quantum key distribution (QKD) threatens to change this dynamic for good. With this method, one party can send a cryptographic key encoded with photons to another party. The unique properties of photons as quantum objects are such that any attempt to "measure" (or decipher) the message will change the photons' quantum state. The Heisenberg Uncertainty Principle ensures that the message will then be destroyed or altered, making it easy for both the sender and receiver to see that the message has been compromised.
Thus, QKD doesn't rely on preventing interception or decryption, but rather on detecting eavesdropping and self-destructing the message as a result.
Moreover, in early September of this year, scientists in Japan announced the inauguration of the Tokyo QKD Network, an international collaboration between companies across Europe and Asia whose goal is to build a quantum encryption network that enables secure transmissions between as many as 64 computers within a network. Ultimately, this will increase the commercial viability of quantum encryption and open up the doors for wider use.
Today, the encrypted communications market is estimated to be worth $20 billion. Quantum encryption already protects both sensitive national security information in the public sector and financial information in the private sector. Its security is tested and proven.
And while many people believe that this kind of security is only suited for limited applications -- Swiss banks and large government agencies, for example -- quite the opposite is true. Today we are seeing quantum cryptography spread to more traditional business and consumer security applications, and with technological innovations and improvements in infrastructure, the coming decades will see that spread intensify. While it will take time and significant resources to convert organizations and individuals to using QKD, in the end the unbeatable security of this technology, when combined with convenience, will make it a no-brainer.
Here is just a small sample of current and near-future applications of quantum cryptography:
1. Ultra-Secure Voting
With political upheaval and accusations of voter fraud rampant in developed and developing countries alike, it’s clear that making the voting process more secure is a necessity. Since 2007, Switzerland has been using quantum cryptography to conduct secure online voting in federal and regional elections. In Geneva, votes are encrypted at a central vote-counting station. Then the results are transmitted over a dedicated optical fiber line to a remote data storage facility. The voting results are secured via quantum cryptography, and the most vulnerable part of the data transaction (when the vote moves from counting station to central repository) is uninterruptible. This technology will soon spread worldwide, as many other countries face the specter of fraudulent elections.
2. Secure Communications with Space
Secure communications with satellites and astronauts is an increasing concern, and a company called QuintessenceLabs is working on a project for NASA that will ensure secure communications from Earth with satellites and astronauts. The goal of the project is to achieve a protocol which guarantees the security of communications regardless of the technology or intelligence to which an adversary has access. It also includes a mandate to secure both information “at rest” and in transit. This would ultimately increase the safety of astronauts in space and ideally preclude the needs upgrade in the future beyond minor speed increases.
3. A Smarter Power Grid
It has been speculated that the American power grid is one of the most vulnerable targets for a cyber attack. In fact, some major U.S. utilities are under “constant” attack by cyber enemies. A small encryption device called the QKarD could put an end to that fear. Using the QKarD, workers would be able to send totally secure signals using public data networks to control smart electricity grids. Smart grids are essential for balancing supply and demand for efficiency. Additionally, with proper precautions in place, they are significantly more secure than traditional grids. With the QKarD or a similar quantum encryption device, we would be able to defend and guarantee the safety of our infrastructure against attacks.
4. Quantum Internet
Today’s internet is relatively fast, but its security is paltry compared to quantum-encrypted transmissions. So why don’t we transmit everything using QKDs? Well, for one, quantum encryption would greatly slow down the internet. In the future, however, it’s possible that we could switch seamlessly between “regular” and “quantum encrypted” internet, so that our most sensitive transmissions would be passed along in an ultra-secure manner. This would achieve the ideal of a simultaneously fast and secure internet.
With the rise of Facebook, Twitter and other social networks, the previous decade has been one of rampant and unchecked sharing. However, the coming years are likely to see a much greater focus on issues of security, privacy and individual protection. When the new iPhone comes out, for example, owners will be able to access them using fingerprints, adding a whole new layer of security: biological identification. As devices become more “wearable” and screens increasingly disappear, biometrics are likely to become a huge part of how we secure them.
When it comes to transmitting sensitive information between two or more points, however, we need something stronger. It’s likely that QKDs and other quantum encryption methods will fill in the gap and allow us to secure sensitive information more effectively in the future. Quantum encryption is a powerful and positive step in the right direction, toward a future in which we can feel more secure about how and what we share.