The Post-Quantum Threat: Why Hackers Are Stealing Encrypted Data They Can’t Yet Read

We conclude our list of threats for 2026 with a look into the future. You may have heard of quantum computers—those supercomputers that will revolutionize science. But did you know that they will have the power to instantly crack almost any password used today?

Although a stable quantum computer is still a few years away, hackers have already launched their attack. Their strategy is called Harvest Now, Decrypt Later. At Altanet Craiova, we want to stay one step ahead and explain why your encrypted data today could be exposed tomorrow.

What does “Harvest Now, Decrypt Later” mean?

Today, when you send a confidential email or make a bank transaction, the data is encrypted. A hacker who intercepts the traffic sees only a string of meaningless characters. With current technology, it would take them 1,000 years to break that encryption.

But hackers think long-term:

• Step 1 (Today): Hackers steal encrypted databases from companies or governments and store them on cheap servers. They can’t read them, but they guard them jealously.
• Step 2 (In the future): When quantum computers become accessible (estimated 2029–2030), they will use that massive computing power to instantly crack the old encryption.
• The result: Secrets stolen in 2026 will become visible.

Who should be worried?

If your data expires quickly (for example, a price offer valid for 3 days), you have nothing to fear. But if you handle information that needs to remain secret for 10–20 years, you have a problem:

• Medical records: A person’s medical history is sensitive throughout their entire life.
• Banking data and Social Security numbers: A person’s identity does not change.
• Trade secrets: A product’s formula or a building’s blueprints remain valuable for decades on end.

How do we prepare for the quantum era?

The tech world isn’t sitting idle. Work is already underway on Post-Quantum Cryptography (PQC)—new mathematical algorithms that cannot be broken even by quantum computers.

• Don’t use outdated encryption: Outdated algorithms (such as MD5 or SHA1) are already vulnerable. Make sure your systems use modern standards (AES-256).
• Crypto-Agility: Build your applications so that you can easily switch encryption methods when new standards are approved, without having to rewrite all your software.

To better understand the race against time behind this technology, you can read IBM’s explanations about quantum cryptography.

Conclusion

Cybersecurity is not a destination, but an ongoing journey. From mundane fake phone calls (vishing) to the quantum threats of the future, the only constant is change.

The Altanet Craiova team is here to help you navigate these challenges. Whether you need to secure your laptop or conduct an audit for your entire company, visit our contact page and let’s build a secure digital future together.

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This material is part of Altanet’s educational series on digital security. Want to know what other risks you’re facing this year? See the complete list of cyber threats for 2026.