Cryptography – the backbone of modern digital security- is facing its greatest challenge to date. By the end of 2025, quantum computing is no longer a distant laboratory concept, but an imminent threat with clear timelines. Quantum algorithms such as Shor’s have the theoretical ability to break widely used encryption systems like RSA and ECC (Elliptic Curve Cryptography) in a matter of minutes. This threat doesn’t just affect future data—it puts all sensitive information being intercepted and stored today at risk, waiting to be decrypted once quantum computing becomes fully operational.
The risk is real, and the solution is known as Post-Quantum Cryptography (PQC): a long-term race to develop systems that can withstand quantum machines.
Harvest Now, Decrypt Later: A Growing Threat
Organizations and governments are confronting what is known as the “harvest now, decrypt later” (HNDL) threat. Attackers—including nation-states—are actively intercepting and storing encrypted data today, fully aware that they will be able to decrypt it as soon as sufficiently powerful quantum computers become available. This includes trade secrets, military intelligence, and personal data with long-term value.
As a result, migrating to PQC standards has become a national security priority for many advanced economies. The cost of doing nothing is far greater than the cost of migration.
PQC Migration: From NIST Standards to Enterprise Adoption
The driving force behind the new standards is the U.S. National Institute of Standards and Technology (NIST). After years of competition and evaluation, NIST has selected the core algorithms that will form the foundation of post-quantum cybersecurity.
The algorithms now being adopted by organizations include:
- CRYSTALS-Kyber: The new standard for key establishment (encapsulation), essential for secure communications such as TLS/SSL.
- CRYSTALS-Dilithium: The standard for digital signatures, ensuring the authenticity of data and software.
For companies across Spain and Europe, one of the major tasks in 2026 will be creating a cryptographic inventory. Identifying where vulnerable algorithms like RSA are currently in use is critical in order to plan their replacement with PQC-compliant alternatives.
Challenges for 2026: Cryptographic Agility
The biggest challenge organizations face in 2025 is cryptographic agility. Many legacy systems have encryption tightly embedded in hardware or software, making upgrades difficult and costly. Future cybersecurity solutions must be designed with the ability to quickly swap or update cryptographic algorithms as threats evolve.
The recommended approach is the implementation of so-called “hybrid mode.” This model combines today’s classical encryption (RSA) with the new PQC standard (Kyber) simultaneously. If classical encryption is compromised, the communication channel remains protected by PQC, ensuring data confidentiality throughout the transition.
The post-quantum era represents a fundamental restructuring of the internet and enterprise security. Organizations that begin their migration strategy in 2026 will be far better positioned to protect their most valuable information against the most powerful cyber threat in history.
