For many years, the Rivest–Shamir–Adleman (RSA) algorithm has been the quiet hero behind secure websites, software updates, virtual private networks, and digital documents. It works because finding the prime number factors of a very large number is extremely hard for the computers we use today. Its strength lies in math: factoring very large prime numbers is nearly impossible for the computers we use today. With a key length of two thousand forty-eight bits, it has been more than strong enough for everyday protection across the internet and in the enterprise.

How quantum computing changes the story

Quantum computing rewrites the equation. A cryptographically relevant quantum computer can find those prime number factors dramatically faster than any traditional computer. When that becomes feasible, the basic promise of this algorithm collapses. What used to take an unimaginable amount of time could become doable, allowing attackers to impersonate trusted services or unlock protected data.

You might think this is only a future problem. It is not. Attackers can record your encrypted data now and hold it until quantum computers are ready. If that data needs to stay private for years, you cannot wait to begin planning. There is also a very practical reason to act early: changing the cryptography in complex systems is slow, cross-functional work. It touches applications, network devices, cloud services, and the way teams build and ship software. No one wants to rush this during a critical incident.

What will break and what will hold

RSA algorithm is not alone. Other public-key methods rely on number problems that a large, fault-tolerant quantum computer could also break. That includes classic Diffie–Hellman key exchange, the Digital Signature Algorithm, and the family of elliptic-curve methods used across the internet today for both key exchange and digital signatures.

But not everything falls apart. Symmetric encryption, such as the Advanced Encryption Standard, and secure hash families are not broken outright by quantum computing. They may need larger key sizes or longer digests to keep the same safety margin, but they do not face the same cliff as the public-key methods above. That context helps leaders avoid the myth that “quantum breaks everything.”

The good news is that quantum-safe algorithms are here. Many organizations will move in two phases:

• First, they will combine today’s methods with quantum-resistant methods during a transition period.
• Second, they will switch fully to quantum-resistant methods once their tools, partners, and regulators are ready. This staged approach reduces risk while teams learn and tune performance

Before you move, know the ground you stand on

Getting ready starts with visibility. You need to know where the algorithms appear across your environment: on web servers and gateways, in containers and mobile apps, inside databases and message brokers, and in embedded devices. Business context matters too. A forgotten test service is not the same as the system that processes customer payments. From there, set simple, measurable rules: which systems migrate first, how to test, and how to measure progress. Expect larger keys, larger messages, and sometimes new hardware needs. Plan for those realities rather than being surprised by them.

Clear communication is just as important. Security, platform, and application teams need a shared view of what is changing and why. Executives need clear milestones and evidence of risk reduction. Auditors will ask for records that show policy, exceptions, and remediation. The more you can automate discovery, policy checks, and reporting, the smoother this transition will be. This journey is not only about defending against a new kind of technology. It is about building the habit of changing cryptography without drama. Algorithms age. Standards evolve. New threats appear. Organizations that can swap cryptography in a controlled, measured way will move faster and adapt better.

From discovery to remediation: Achieve crypto-agility with IBM Guardium Cryptography Manager

IBM Guardium Cryptography Manager is built to make that happen. It finds where cryptography is used, builds an inventory that links algorithms, keys, certificates, libraries, and protocols to the systems and services that rely on them, and checks everything against clear policies. It highlights what is at risk, shows which systems still depend on the outdated algorithms and produces simple reports for teams, leaders, and auditors. It also connects to ticketing tools to move from issue to verified fix and confirms that changes worked in production. With Guardium Cryptography Manager, you can plan and execute your move to quantum-safe methods, including those advanced by IBM researchers, and you can build the long-term habit of changing cryptography as your business evolves.