Reading time: 9 minutes | Last updated: October 2025 | Category: Cybersecurity & Privacy

Quantum Computing and Privacy: The Encryption Threat

Meta Description: Quantum computers could soon break today's encryption. Learn what that means for your privacy and how post-quantum cryptography keeps you safe.

TL;DR: The Quick Version

  • Quantum computers could break modern encryption within 10-20 years, exposing everything from bank accounts to private messages
  • Governments are racing to adopt post-quantum cryptography (PQC) before 2035 to protect global privacy
  • The "harvest now, decrypt later" threat means your data may already be at risk
  • NIST published the first post-quantum standards in August 2024 (FIPS 203, 204, 205)
  • Simple fixes work: Use strong passwords, enable 2FA, keep software updated
  • You're not helpless: A 20-minute security checkup today eliminates 80% of your risk
Abstract chip circuit board technology background representing quantum computing and encryption

Image: Abstract Chip Circuit Board Technology Background

Quantum computers pose a significant threat to current encryption methods that protect our digital privacy.

If you're reading this on a secure connection—and you almost certainly are—congratulations. You're currently protected by encryption that would take a regular computer millions of years to crack.

Here's the problem: quantum computers don't play by the same rules. And they're coming faster than most people realize.

Your bank passwords, medical records, private messages, and basically every digital secret you have is protected by mathematical locks that are about to become pickable. Not in some distant sci-fi future. We're talking about a realistic timeline that has the White House, tech giants, and security experts scrambling right now.

Here's where things get real.

Let me explain what quantum computing privacy threats mean for you, why quantum encryption threats are already being exploited through "harvest now, decrypt later" attacks, and how post-quantum cryptography is racing to protect your data before it's too late.

What Is a Quantum Computer? Understanding the Technology That Could Break Encryption

Before we talk about your privacy imploding, let's talk about what makes quantum computers different from the laptop you're using right now.

Your regular computer—whether it's a phone, laptop, or server—processes information in bits. Each bit is either a 1 or a 0, on or off, yes or no. It's binary, straightforward, and it's how we've been computing for decades.

Quantum computers work with something called qubits, and this is where things get weird. A qubit can be 1, 0, or—here's the kicker—both at the same time. It's a quantum physics thing called superposition, and it sounds impossible because it kind of is, at least to our everyday understanding of reality.

Think of it this way: if a regular computer is trying every key on a massive keyring one at a time to unlock a door, a quantum computer can try multiple keys simultaneously. For certain types of problems—specifically the math problems that protect your data—this makes quantum computers terrifyingly good.

We're not talking about playing video games faster or loading websites quicker. Quantum computers are purpose-built for very specific tasks, and unfortunately for all of us, one of those tasks is cracking the encryption that currently protects almost everything online.

How Quantum Computers Break Encryption: The Math That Keeps Your Secrets Safe (For Now)

Most of the internet's security relies on something called public key cryptography. The two big algorithms doing the heavy lifting are RSA and elliptic curve cryptography (ECC). You don't need to understand the math—just know that these systems are based on problems that are really, really hard for regular computers to solve.

RSA, for example, relies on factoring large numbers. If I give you the number 35 and ask you what two prime numbers multiply to make it, you can figure out it's 5 and 7 pretty quickly.

But if I give you a number with 617 digits and ask the same question? Even the most powerful supercomputer we have would need more time than the age of the universe to figure it out.

This is why your credit card works online. This is why your messages in Signal are private. This is why you can trust that your bank's website is actually your bank's website. The math is so hard that breaking it is, for all practical purposes, impossible.

Unless you have a quantum computer.

In 1994, a mathematician named Peter Shor developed an algorithm—creatively called Shor's algorithm—that could use quantum computers to factor those huge numbers in a reasonable amount of time. Not millions of years. Not thousands. We're talking hours to days.

Researchers calculated that a quantum computer with about 20 million noisy qubits could break a 2048-bit RSA key in roughly 8 hours. For context, 2048-bit RSA is what most secure websites use right now. It's considered completely safe against conventional attacks.

The encryption that would take a classical computer 300 trillion years to crack? A sufficiently powerful quantum computer could theoretically do it before your lunch break ends.

We Don't Have These Super-Powerful Quantum Computers Yet... Right?

Correct. We don't have quantum computers powerful enough to break real-world encryption. Yet.

Google, IBM, and other companies have built quantum computers with dozens to hundreds of qubits, but they're noisy, error-prone, and nowhere near the millions of stable qubits needed to run Shor's algorithm against actual cryptography.

Many scientists believe it's "merely a significant engineering challenge" at this point, not a question of if, but when. Some estimates suggest we could see cryptographically relevant quantum computers—computers powerful enough to break current encryption—within 10 to 20 years. Maybe sooner. Maybe later. Nobody knows for sure.

Here's what security experts know for certain: it has historically taken almost two decades to deploy major cryptographic infrastructure changes. SSL/TLS, the little padlock you see in your browser? That took roughly 20 years to become universal.

So even if quantum computers capable of breaking encryption are 20 years away, we needed to start preparing yesterday.

The "Harvest Now, Decrypt Later" Attack: Why Quantum Encryption Threats Matter Now

But there's a more immediate threat, and it's already happening.

Right now, sophisticated adversaries—think nation-states and well-funded criminal organizations—are recording massive amounts of encrypted internet traffic. They can't read it today. But they're storing it anyway.

Why? Because they're betting on quantum computers.

It's called "harvest now, decrypt later," and it's exactly what it sounds like. Grab the encrypted data now, store it, wait for quantum computers to become available, and then decrypt everything retroactively.

If you sent a sensitive message in 2025 that's protected by today's encryption, and a quantum computer becomes available in 2035, that message can be decrypted and read. The data you thought was permanently safe is just sitting in a vault, waiting.

For most everyday communication, this might not matter. Who cares about your grocery list from 10 years ago? But if you're a government official, a researcher, a business with trade secrets, or someone with sensitive medical or financial information, this is a real problem.

Some secrets need to stay secret for decades, not just until the technology catches up.

The White House explicitly warned federal agencies in their National Security Memorandum 10 (2022) that "encrypted data can be recorded now and later decrypted by operators of a future" quantum computer. This isn't theoretical anxiety—it's operational reality that governments are actively preparing for.

What Is Post-Quantum Cryptography? How We're Fighting Back

The good news? We're not sitting around waiting for the apocalypse.

Cryptographers and mathematicians have been working on post-quantum cryptography (PQC)—encryption systems designed to resist attacks from both classical and quantum computers. These new algorithms are based on different types of hard math problems that even quantum computers struggle with.

In August 2024, the National Institute of Standards and Technology (NIST)—basically the U.S. government's standards authority for this stuff—published the first three post-quantum cryptographic standards: FIPS 203, FIPS 204, and FIPS 205. These are derived from algorithms called CRYSTALS-Dilithium, CRYSTALS-KYBER, and SPHINCS+.

These aren't just theoretical. They're production-ready algorithms that companies and governments can start implementing right now.

The White House issued a memorandum in November 2022 directing all federal agencies to inventory their cryptographic systems and prepare for migration to post-quantum cryptography, with the explicit goal of "mitigating as much of the quantum risk as is feasible by 2035."

That's the timeline we're working with: 2035. Just over a decade to rebuild the foundational security infrastructure of the internet.

The Transition to Post-Quantum Cryptography Is Going to Be Messy

Here's where it gets complicated—and frankly, expensive.

Switching from current encryption to post-quantum encryption isn't like updating your phone's operating system. We're talking about billions of devices, countless software systems, embedded hardware in cars and medical devices, and infrastructure that was built decades ago and never expected to need an upgrade.

Why Migration Takes Decades

Some devices are too old or too limited to run the new, more computationally intensive post-quantum algorithms.

What do you do with a medical device that was built in 2015 and is expected to last another 15 years? Or industrial control systems that were designed in the early 2000s?

What Happens to Older Devices

The answer for many organizations is hybrid cryptography—using both old and new encryption systems simultaneously. You protect data with both RSA and a post-quantum algorithm, so even if one fails, the other still works.

It's belt-and-suspenders security, and it's expensive and complex to implement.

NIST has been running a competition since 2016 to evaluate post-quantum algorithms, with multiple rounds of testing, analysis, and refinement. Even with the first standards now published, there are still additional algorithms being evaluated because this is too important to get wrong.

And organizations are understandably cautious. Nobody wants to be the first to adopt a new standard that turns out to have a flaw. But nobody wants to be the last, either, especially with that "harvest now, decrypt later" problem looming.

What Quantum Computing Privacy Threats Mean for You

Let's bring this back to you.

If you're using modern, updated software and services—banking apps, messaging platforms, email, cloud storage—you're probably going to be fine. The big tech companies and financial institutions are working on this transition because they have to.

Your bank isn't going to let quantum computers compromise your account without a fight.

But here's what you should know:

Your old data is vulnerable. Anything sensitive you've transmitted online that someone might have recorded could theoretically be decrypted in the future. For most of us, this isn't a crisis. For some, it is.

Legacy systems are the real problem. Older devices, industrial systems, and embedded technology that can't be easily updated are going to remain vulnerable, possibly for decades. This affects critical infrastructure—power grids, transportation systems, healthcare equipment.

The transition timeline is tight. We have maybe 10-15 years to overhaul global cryptographic infrastructure before quantum computers potentially become a real threat. That's an ambitious timeline even in the best circumstances.

Not everyone will upgrade in time. Some companies will drag their feet. Some systems will be impossible to upgrade. There will be gaps, and those gaps will be exploited.

The internet was originally designed to be decentralized and resilient—able to route around damage, even nuclear war. Now? We've concentrated so much power and infrastructure in a handful of systems that when something breaks, it breaks everywhere.

Quantum computing is about to stress-test that fragility in a whole new way.

That might sound far off—but it's closer than you think.

How to Protect Your Privacy from Quantum Threats: What You Can Actually Do

For most regular people, there's not a ton of direct action to take right now. You're not personally responsible for migrating enterprise cryptographic systems.

But here's what you can do:

Stay updated. Use modern, actively maintained software. Companies that care about security are already working on post-quantum transitions. Old, unmaintained apps are where you're most vulnerable.

Be aware of the timeline. This isn't a problem for next week, but it's not science fiction, either. If you're making long-term security decisions—for a business, for sensitive data, for infrastructure—factor in the quantum threat.

Pressure companies to take this seriously. Ask your bank, your healthcare provider, your employer about their post-quantum cryptography plans. The more customers care, the more companies prioritize it.

Don't panic, but don't ignore it. The sky isn't falling tomorrow. But the foundation of internet security is shifting, and pretending it's not happening doesn't help anyone.

The White House is mandating federal agencies submit annual inventories of cryptographic systems until 2035. That's how seriously the government is taking this. It's not alarmist to pay attention.

The Real Question Nobody's Asking

Here's what really gets me about this whole thing: we saw this coming. Shor's algorithm was published in 1994. We've known for over 30 years that quantum computers could break current encryption. NIST started working on post-quantum standards in 2016.

And yet, we're still scrambling. Still pushing timelines. Still hoping we have enough time.

It's the same pattern we've seen with every major infrastructure problem. Remember Y2K? The millennium bug didn't destroy civilization, but only because thousands of engineers spent years frantically fixing code. Remember the AWS outage I wrote about recently? We know single points of failure are dangerous, but we keep building systems that depend on them anyway.

With quantum computing, we're watching the same movie play out again. We know the threat. We know what needs to happen. We're just not sure if we'll actually do it in time.

The concentration of cryptographic responsibility in a handful of major cloud providers and tech companies means that when they transition to post-quantum cryptography, billions of users will benefit automatically. That's the good news.

The bad news? That same concentration means if those transitions don't happen, or happen too slowly, or are implemented incorrectly, billions of users are exposed simultaneously. It's the data center problem all over again, except this time the vulnerability isn't a DNS outage—it's the mathematical foundation of privacy itself.

Where We Go From Here

The transition to post-quantum cryptography is underway. Standards are published. Federal mandates are in place. Companies are testing implementations. Researchers are refining algorithms.

But it's a race against time, against budget constraints, against technical limitations, and against the steady march of quantum computing development.

Will we make it? Probably. The stakes are high enough that governments and corporations are actually taking this seriously, which is more than you can say for most long-term threats.

But "probably" isn't the same as "definitely," and when we're talking about the privacy and security of basically every digital interaction happening on the planet, "probably" should make us all a little uncomfortable.

Right now, your data is safe behind math problems that are functionally impossible to solve. In ten years? Twenty? We're betting everything that we can build new locks before quantum computers build the ultimate lockpick.

I hope we're right.

But after watching how slowly we respond to known threats—from cybersecurity to infrastructure to climate—I'm not holding my breath.

The quantum threat is real. The timeline is uncertain. The consequences are enormous. And just like with every other systemic challenge we face, we're going to wait until the last possible moment, scramble to fix everything, and hope it's enough.

It usually is. Until it isn't.

About the Author

This article was written by cybersecurity researchers specializing in encryption, quantum computing threats, and digital privacy. Our team has been tracking post-quantum cryptography developments since NIST began its standardization process in 2016. We believe in making complex security topics accessible to everyone—because your privacy shouldn't require a PhD to protect.

FAQ: Quantum Computing and Privacy

Will quantum computers steal my passwords?
Not directly. Quantum computers threaten the encryption that protects data in transit and the cryptographic systems used for authentication, but they don't magically hack passwords. However, if your password was transmitted using vulnerable encryption that was recorded, it could theoretically be decrypted later. Use strong, unique passwords and enable two-factor authentication regardless.
When will quantum computers actually break encryption?
Nobody knows exactly. Estimates range from 10 to 30 years, but some experts think it could happen sooner. The key thing is that we need to act now because cryptographic transitions take decades, and data can be harvested today for later decryption.
Is my iPhone/Android phone vulnerable?
Modern smartphones from major manufacturers will likely receive updates as post-quantum cryptography becomes standard. Apple and Google are both involved in the transition. The bigger concern is older devices that no longer receive security updates and embedded systems that can't be updated at all.
What is post-quantum cryptography?
Post-quantum cryptography (PQC) refers to cryptographic algorithms that are designed to be secure against attacks from both classical and quantum computers. These algorithms are based on different mathematical problems that quantum computers can't efficiently solve, unlike current systems based on factoring and discrete logarithms.
Should I stop using online banking or shopping?
No. Current encryption is still secure today, and major financial institutions are actively working on quantum-resistant solutions. The threat is future quantum computers decrypting data that's being collected now. For everyday transactions, continue using secure, updated services from reputable companies.
What are the new post-quantum algorithms NIST approved?
In August 2024, NIST published three standards: FIPS 203 (based on CRYSTALS-KYBER for encryption), FIPS 204 (based on CRYSTALS-Dilithium for digital signatures), and FIPS 205 (based on SPHINCS+ as a backup signature scheme). These are the first official post-quantum cryptographic standards ready for implementation.
Can I use post-quantum encryption right now?
Some implementations are available, but widespread adoption is still in progress. Major tech companies and security vendors are beginning to deploy post-quantum solutions, often using hybrid approaches that combine traditional and quantum-resistant algorithms. For individual users, the best approach is to use modern, updated software from vendors committed to the transition.
What is "harvest now, decrypt later"?
This is a threat model where adversaries record encrypted data today, even though they can't decrypt it, with the intention of decrypting it in the future when quantum computers become available. This is particularly concerning for sensitive information that needs to remain confidential for decades, like government secrets, medical records, or intellectual property.
Will blockchain and cryptocurrency be affected?
Yes, potentially. Many blockchain systems rely on cryptographic algorithms that are vulnerable to quantum attacks, particularly the digital signature schemes used to authorize transactions. The cryptocurrency community is aware of this threat and various projects are researching quantum-resistant alternatives, but it remains a significant challenge for the industry.
Why can't we just make longer encryption keys?
Making keys longer helps against classical computers but doesn't fundamentally solve the quantum problem. Quantum computers using Shor's algorithm can break RSA and elliptic curve cryptography regardless of key length—it just takes a bit more time. Doubling the key length against a quantum computer provides far less security improvement than it does against classical attacks. That's why we need entirely different algorithms, not just bigger keys.
Is the government spying on me with quantum computers?
Current quantum computers aren't powerful enough to break real-world encryption. However, government agencies are certainly aware of the quantum threat and are actively preparing for the transition to post-quantum cryptography. The bigger concern is that powerful adversaries may be collecting encrypted data now for future decryption.
What happens if we don't transition in time?
If sufficiently powerful quantum computers become available before we complete the transition to post-quantum cryptography, we could face widespread compromise of digital security. This could affect everything from financial transactions to government communications to personal privacy. The impacts would be severe, which is why governments and industry are treating this as a critical priority.
Who is most at risk?
Organizations with long-lived secrets (government, defense, healthcare, research), critical infrastructure operators, and anyone unable to quickly update their cryptographic systems. Individuals using modern services from responsible providers are at lower risk, but those relying on old devices or unmaintained software are more vulnerable.