Harvest Now, Decrypt Later: The Quantum Threat That Has Already Begun

A Quiet Threat with Massive Consequences 

Cyber attackers are stealing encrypted data today and planning to decrypt it later when quantum computing becomes powerful enough to break current encryption standards. This threat is already in motion. 

Known as Harvest Now, Decrypt Later or HNDL, this tactic is built on patience. Sophisticated threat actors are gathering sensitive data from financial institutions, healthcare organizations, law firms, and governments. Their goal is not to use it now but to unlock it in the future. 

As quantum computing advances and surpasses traditional computing capabilities, the cryptography protecting this stolen data will become ineffective. Once that happens, everything from trade secrets to classified communications could be exposed. 

What is a Harvest Now, Decrypt Later attack 

HNDL is a long-term strategy. Threat actors collect encrypted data with the intention of decrypting it once quantum computing becomes available. 

This is not a guessing game. It is calculated and targeted. Cybercriminals understand which encryption standards are vulnerable to quantum attacks. They also know which data will retain value five, ten, or even twenty years from now. 

The attack consists of three core phases: 

1. Harvesting encrypted data from compromised systems 

2. Storing and managing it securely and quietly 

3. Decrypting it once quantum capabilities become available 

This approach is already underway, even though most organizations are still focused on today’s risks. The damage will come later, but the breach is happening now. 

Why this affects cybersecurity 

Cybersecurity is fundamentally built on trust and encryption. The assumption is that encrypted data is secure. HNDL breaks that assumption. 

This changes the playing field for several reasons: 

• Current encryption methods like RSA and ECC will eventually be broken by quantum computers 

• Stolen data can be silently stored for years without detection 

• The value of certain information persists for decades, making it a prime target 

• Organizations are often unaware that this risk even exists 

For cybersecurity teams, this means protecting against a future breach that results from today’s activity. It introduces a new kind of urgency, one that requires long-term thinking and proactive change. If organizations wait until quantum computing is mainstream, it will already be too late. 

Industries most at risk 

Some industries are particularly vulnerable to HNDL attacks because the value of their data is long-lasting. 

Finance 
Customer records, banking transactions, investment strategies, and credit data could be used for future fraud and exploitation 

Healthcare 
Medical histories and personal health information have a long lifespan and can be used for identity theft or blackmail 

Government and defense 
Classified documents, strategic communications, and national security data must remain confidential for decades 

Legal and corporate IP 
Trade secrets, M&A information, and intellectual property are highly sensitive and could damage companies or give competitors an unfair advantage 

The quantum threat timeline 

Experts estimate that quantum computers capable of breaking today’s encryption could arrive by 2030. That is just a few years away. 

It takes time to prepare. Post-quantum cryptography is still evolving, and many systems are not designed for crypto agility. Organizations need to understand that this is not just a technology problem. It is a risk management and compliance issue that must be addressed at the leadership level. 

How to prepare now 

Classify long-term sensitive data 
Start by identifying what needs to stay protected for the next decade or more. Not all data is equally valuable over time 

Monitor cryptographic developments 
Stay up to date with NIST and other authorities standardizing post-quantum encryption methods 

Build crypto agility 
Ensure your infrastructure can adapt quickly to new encryption standards without major disruption 

Invest in expert guidance 
Work with cybersecurity partners who are already preparing for quantum risks and understand how to align strategy, operations, and technology 

Cyber Certainty starts now 

At CYPFER, we help organizations prepare for what is coming next. From real-time threat monitoring to long-term risk advisory, we work side by side with your teams to protect data that matters. 

We operate globally, 24 hours a day, without outsourcing. Our experts are in the trenches responding to live threats and building roadmaps for a future that includes quantum disruption. 

Cyber Certainty is not a promise for today. It is a strategy for tomorrow. 

Talk to us 

The quantum threat is real and approaching fast. Harvest Now, Decrypt Later attacks are happening now and will only increase in scale and impact. Do not wait until it is too late. 

Contact CYPFER today to assess your quantum risk exposure and prepare your organization for what comes next.