The Quantum Clock Is Ticking: What is Harvest-Now, Decrypt-Later?

Type: Briefing
Published: June 2025
Keywords: Harvest-Now, Decrypt-Later (HNDL), RSA-2048 / ECC break risk, Quantum-computer timeline acceleration, Long-lived sensitive data retention

Abstract

Attackers are quietly collecting encrypted data today so it can be broken with tomorrow’s quantum computers. This article explains the harvest-now, decrypt-later (HNDL) threat, why the risk window is shrinking, and what it means for any developer or decision-maker who handles long-lived sensitive data.

Key Points at a Glance

What Is Harvest-Now, Decrypt-Later?

Traditional cyber-crime cashes in immediately. HNDL flips the script: attackers passively exfiltrate or divert encrypted data today and file it away until a cryptographically relevant quantum computer (CRQC) arrives. With Shor’s algorithm, that machine will slice through RSA and elliptic-curve keys, turning archives of useless ciphertext into readable gold.

Why the Timeline Is Accelerating

In early 2025, Google Quantum AI showed that RSA-2048 could, in theory, be factored with ≈1 million noisy qubits running one week—down from previous estimates of 20 million. Meanwhile, IBM’s roadmap targets fault-tolerant machines before 2030. Government and industry are reacting fast: NIST’s ML-KEM & ML-DSA became U.S. standards in August 2024, and Germany’s BSI—joined by 17 EU states—calls for quantum-safe protection of sensitive systems no later than end-2030.

Your Old Data Won’t Stay Secret

Regulations force organisations to keep data far longer than most encryption lifecycles:

Imagine this: your company’s confidential contracts from 2015—once thought safe behind RSA-2048—suddenly leak to a hacker in 2030. Would that cost you? If the answer is “yes,” that is exactly the scenario looming if HNDL isn’t taken seriously.

Real-World Sightings of HNDL

The strategy is not hypothetical. Internet route hijacks in 2016 (Canadian traffic via China), 2019 (European mobile traffic via China Telecom) and 2020 (U.S. tech traffic via Russia) diverted vast encrypted flows—perfect HNDL fodder. Intelligence briefings from NSA and FBI confirm adversaries are “stealing massive volumes of encrypted data and shelving it until quantum techniques emerge.”

Takeaways for Developers & Decision-Makers

Next Step

Ready to go deeper? Our follow-up article covers real-world post-quantum deployments and new government rules shaping this transition.

Read Part 2 →