"Harvest now, decrypt later" has become the phrase on everyone’s lips when discussing post-quantum cryptography. The idea is simple: Adversaries collect encrypted data today and wait for the arrival of quantum computers that can break current encryption methods. But is this really the only threat we should focus on?
The Evolution of Quantum Risk Awareness
Five years ago, quantum computing’s impact on cryptography was an esoteric topic, difficult to translate into business language. For many key decision-makers, quantum computing was a distant, academic problem, something that might be relevant in 10 years or more. At that time, there were no official standards — after all, the National Institute of Standards and Technology (NIST) only issued its first post-quantum cryptography (PQC) standards in August 2024.
Then, a compelling argument emerged: Retrospective decryption. This threat suggested that encrypted data stolen today could be deciphered once quantum computers become powerful enough to break conventional cryptographic algorithms. The fear of this scenario helped build a business case for quantum-resistant security solutions, making the problem tangible and relevant.
However, we are now halfway through that 10-year horizon. The problem is no longer just about securing data against future threats. Instead, the transition to quantum-resistant cryptography is a monumental shift that will impact multiple areas of digital infrastructure.
Beyond "Harvest Now, Decrypt Later" Attacks: The Wider Impact of Quantum Computing
Quantum computers will not only make past data vulnerable but will also disrupt the fundamental security mechanisms we rely on today. This extends far beyond just encryption and affects a range of industries and technologies, from identity verification to financial transactions.
Identity and Authentication Systems
- Physical Identity Cards and Passports: Government-issued ID cards, driver’s licenses, and passports are typically valid for a decade or more. Any new procurement cycles should include quantum-safe cryptographic mechanisms in the embedded chip security.
- EU Digital Identity Wallet: This digital equivalent of government-issued IDs should be proactively addressing quantum threats to ensure long-term security and interoperability across Europe.
- User Authentication: Many authentication methods, including mobile authenticators, FIDO2 passkeys, and X.509 PKI, must be upgraded to post-quantum alternatives. Even seemingly minor security elements, such as JSON Web Tokens (JWTs) used for user claims, require an upgrade.
Financial Infrastructure
- Payment Cards and Banking Systems: While payment cards have a shorter lifecycle than identity documents, transitioning to quantum-resistant encryption requires overhauling entire financial networks. The shift from RSA-based security to quantum-resistant alternatives will be a major industry challenge.
- Digital Signatures in Banking and Contracts: If you rely on digitally signed documents, such as PDFs containing contracts, these signatures will need to be quantum-stamped to retain legal weight. Otherwise, existing contracts could become unverifiable after Q-Day — the point when quantum computers break current cryptography.
- Audit and Transaction Records: Any system that relies on digital signatures for proof of transactions, such as audit logs, must incorporate quantum-safe protections. Otherwise, payment proofs or logged digital operations may become unverifiable.
Blockchain and Secure Infrastructure
- Blockchain and Distributed Ledgers: Many organizations have invested in blockchain to ensure the integrity of data. However, most blockchain networks rely on conventional cryptography. If not upgraded, quantum computers could break the cryptographic chains underpinning their security.
- Telecommunications Security: Many trust-based authentication methods, such as SMS-based two-factor authentication (2FA) and SIM-based authentication, depend on the security of telecom networks. Ensuring these infrastructures adopt quantum-resistant cryptographic protocols is crucial.
Preparing for the Quantum Future
The transition to quantum-safe cryptography is not something that can happen overnight. Organizations need to begin planning now by:
1. Auditing Cryptographic Dependencies: Identify where and how cryptography is used within their systems, including authentication, data storage, and secure communications.
2. Prioritizing Upgrades: Not all cryptographic dependencies require immediate replacement, but understanding the highest-risk areas is essential.
3. Following Standards: Adopting emerging PQC standards from NIST and similar organizations will ensure compatibility with future systems.
4. Engaging with Vendors: Many security solutions come from third-party providers, meaning businesses must push for quantum-safe upgrades in their supply chains.
5. Planning for Hybrid Cryptographic Models: Transitioning to PQC does not need to be a single-step migration. Hybrid approaches combining conventional and quantum-safe cryptography can provide a smooth transition.
Conclusion
While "harvest now, decrypt later" attacks remain a significant concern, the broader implications of quantum computing extend much further. A comprehensive, industry-wide transition to quantum-resistant cryptography is necessary to ensure the security and functionality of our digital world.
Organizations that wait until the last minute will face a far more difficult transition. Now is the time to act — before the quantum threat becomes an imminent crisis.
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