Encryption is one of several cornerstones of a robust information security program. Articles on quantum computing often include the compelling narrative that encryption is at risk, but as with any revolutionary technology, separating hype from reality requires nuance.
This article seeks to provide a practical understanding of the risks posed by quantum computing on modern day encryption standards. In assessing those risks, companies and individuals should consider the following nine reflections on the current state of quantum computing and potential business adjustments that may be required in light of this evolving technology.
First, quantum computing is a fundamentally different technology than regular computing. Consider how normal computers and quantum computers find the correct path out of a complex maze. On the one hand, a normal computer will attempt each possible path, remember dead ends, and eventually will find the correct solution. The more complicated the maze, the longer the computer will take to find the solution. On the other hand, a quantum computer will render a bird’s eye view of the maze and will simultaneously assess the probability of each potential path before identifying the correct solution. Unlike the normal computer, the quantum computer will solve the problem exponentially faster regardless of the size and complexity of the maze.
This fundamental difference explains in part why future quantum computers could perform tasks that even the most powerful normal computers cannot, such as simulating large-scale complex environments needed to research new drugs, understand and predict changing weather patterns, develop new radar systems, and create innovative logistics management solutions. But as with any new technology, future quantum machines could also be used to destroy and cause harm, such as eroding personal privacy by rendering complex models that profile individuals or by weakening the encryption methods that help keep sensitive information confidential, private and secure.
Second, quantum computers currently exist, but useful quantum computers are decades away (if not more). Comparing today’s quantum computers and quantum computers capable of performing the functions above is like comparing fireworks with intercontinental ballistic missiles (ICBMs). Both fireworks and ICBMs have fuses and onboard fuel, both (when lit) go up in the air and come back down, and both are designed with specific explosion in mind. But the science, engineering, and technology behind ICBMs are, to put it mildly, more complex.
The same dynamic goes for today’s quantum computers, which can perform some functions, but they lack the capabilities needed to use them for their intended purposes. Governments, companies, and academia recognize the potential benefits presented by useful quantum computers, but getting there will require significant breakthroughs in science, engineering, and technology, to say nothing of harvesting a qualified and innovative workforce and sustaining significant and ongoing investment.
Therefore, nobody knows for certain when useful quantum computers will arrive, but it is reasonable to assume that they will arrive at some point. Therefore, and that the time to prepare for them is now.
Third, useful quantum computing could weaken encryption. At a high level, encryption is a mathematical formula that scrambles information. Each use of encryption generates a large number that is the mathematical solution to the formula and is the only way to unscramble the information. This "key" must be kept hidden and secured, or the information will not remain protected for long.
Unscrambling the information without the key is possible, but impractical when using a normal computer. Recall the maze analogy. On the one hand, a normal computer will attempt every possible key number until it finds the solution, but this will require such significant amounts of time, that it is essentially impractical. On the other hand, a future quantum computer could determine the key value in days, hours, or even minutes.
Fourth, encryption does more than just keep information confidential. Confidentiality is the best-known use for encryption, but the mathematics behind encryption yield two other essential benefits: integrity (protecting information from being altered) and authentication (verifying whether information was altered). Integrity prevents, for example, malicious actors from committing fraud by altering key details, and authentication verifies whether any alterations were made to the original documents. However, future quantum machines could undermine document integrity without leaving any way to authenticate whether, how, or when alterations occurred.
Fifth, research, development and deployment of quantum-resistant encryption standards are already underway. In some cases,you may be using a device already protected by quantum-resistant encryption standards, such as Apple’s Messages app and Microsoft’s consumer and enterprise services. Additionally, the National Institute for Standards and Technology (NIST) plans to publish new encryption standards for federal agency adoption soon, although an exact date is unknown.
Sixth, quantum-resistant encryption would protect data encrypted in the future, but data encrypted in the past could still be vulnerable. Consider the "harvest now, decrypt later" possibility. If, or when, quantum computing becomes widely available to criminal actors who have previously exfiltrated large quantities of encrypted data, the technology could be used to decrypt and access previously protected personal information.
Seventh, state data breach notification statutes do not contemplate "harvest now, decrypt later." State and federal laws largely exempt, from the definition of a data breach, instances where only encrypted data (without the requisite keys) are compromised. In other words, when a malicious actor exfiltrates encrypted data, such event would not trigger notification obligations under relevant laws as encrypted data without the required key would not constitute a breach of security.
As we enter an age of quantum computing, legislators may consider updating data breach notification law exemptions for encrypted data to distinguish between quantum-vulnerable and quantum-resistant encryption methods.
Eighth, quantum-resistant encryption standards may evolve the meaning of “reasonable security.” State and federal data protection laws acknowledge that perfect cybersecurity is impossible. Instead, they require that organizations implement “reasonable” security measures to safeguard protected information from unauthorized access. What constitutes reasonable security varies depending on the sensitivity of the data, the complexity of the organization handling the data, and other factors.
The meaning of reasonable security evolves over time as technologies change and new threats emerge. Quantum-resistant encryption will almost certainly enter the cybersecurity lexicon as a “reasonable” measure as the profound privacy and security risks stemming from quantum-based attacks will likely spur widespread adoption of quantum-resistant encryption defenses.
Finally, companies can use the above considerations to begin preparing for quantum-computing technology. While quantum-resistant encryption is still on the horizon, there are steps that companies can take now to prepare. For example, companies can: conduct risk assessments on current encryption methods and upgrading encryption standards where available; inventory hardware and software systems and determine whether upgrades are needed to implement quantum-resistant encryption; and assess the current retention and deletion processes of the organization and delete data that is no longer needed.
Republished with permission. The original article, "A Practical Guide to Understanding Quantum Computing’s Potential Threat to Encryption," was published by Law.com on March 25, 2025.
