The Quantum Threat to Information Security: Practical Experience Using IBM Q

Abstract Quantum computing represents a fundamentally new computational paradigm based on quantum-mechanical phenomena such as superposition, entanglement, and quantum tunneling. These effects enable certain computational tasks to be performed more efficiently than on classical digital computers. In theory, quantum computing promises significant reductions in execution time and potentially improved energy efficiency for specific classes of problems. The slowing of traditional hardware scaling trends — often associated with Moore’s Law — combined with advances in nanoscale control technologies, has led to substantial commercial and national-security investments in quantum technologies throughout the 2010s. A landmark moment occurred when Google announced the demonstration of so-called quantum supremacy using its superconducting quantum processor Sycamore. The experiment showed that a quantum device could perform a specific computational task beyond the practical reach of classical supercomputers. While the task itself had no immediate practical application, the demonstration marked a critical milestone in the evolution of quantum computing and provided a concrete benchmark for future developments. Quantum Computing and Information Security The rapid progress of quantum technologies introduces significant implications for information security. Many modern cryptographic systems rely on the computational difficulty of mathematical problems such as: Integer factorization Discrete logarithms Elliptic curve problems Quantum algorithms — most notably Shor’s algorithm — threaten to efficiently solve these problems once sufficiently large, fault-tolerant quantum computers become available. This creates a long-term risk to widely deployed public-key cryptosystems, including RSA and elliptic curve cryptography. Through practical experimentation on the IBM Q platform, it becomes possible to: Implement and test fundamental quantum algorithms. Simulate cryptographic primitives under quantum attack models. Evaluate the scalability and limitations of current hardware. Explore post-quantum mitigation strategies. Although current quantum devices remain in the NISQ (Noisy Intermediate-Scale Quantum) era and are not yet capable of breaking real-world cryptographic systems, the trajectory of development suggests that cryptographic transition planning must begin well before large-scale quantum computers emerge. Strategic Implications The quantum threat to information security is not immediate but is strategically significant: Encrypted data intercepted today may be decrypted in the future ("harvest now, decrypt later"). Critical infrastructure and national security systems require long-term protection horizons. Migration to quantum-safe cryptographic standards must occur proactively. Practical experience using IBM Q demonstrates both the power and current limitations of quantum systems, providing valuable insight into how theoretical quantum threats translate into real-world technological development.