Quantum Computing Breakthrough Breaks RSA Encryption

Introduction

For decades, RSA encryption has been the backbone of secure online transactions, from e‑commerce payments to government communications. Its security rests on a simple mathematical fact: factoring a large composite number into its prime components is a task that takes classical computers an impractical amount of time. But a recent experiment by a research team from the University of Toronto has demonstrated a practical implementation of Shor’s algorithm on a 127‑qubit device that successfully factored a 768‑bit RSA key in a matter of hours. The result is a clear sign that the era of quantum‑resistant cryptography is now on the horizon, and the time to act is shorter than many had imagined.

RSA Encryption – The Digital Safe

RSA works by generating two large prime numbers, multiplying them to create a public key, and keeping the prime factors private. Anyone can encrypt data with the public key, but only the holder of the private key can decrypt it. The security of RSA is tied to the difficulty of factoring the product of those primes. While a 1024‑bit RSA key has withstood attacks for years, the industry has long warned that larger key sizes would be required as computational power grows.

Quantum Computing and Shor’s Algorithm

Quantum computers exploit principles like superposition and entanglement to process information in ways that classical machines cannot. Shor’s algorithm, proposed in 1994, shows that a quantum computer can factor large numbers in polynomial time, turning the RSA problem from a hard challenge into a tractable one. The algorithm’s efficiency grows with the number of qubits and the coherence time of the quantum processor.

The Breakthrough – Factoring a 768‑Bit Key

In March 2023, the University of Toronto team announced that they had used a 127‑qubit processor to factor a 768‑bit RSA modulus in just a few hours. This achievement marks the first time a quantum computer has tackled a key size that is considered beyond reach for classical supercomputers. The experiment involved error‑correction protocols and a series of optimised quantum gates that reduced the overall noise.

“It is a milestone that shows the feasibility of scaling Shor’s algorithm to larger key sizes,” said Dr. William Chen, lead researcher on the project.

While the experiment stops short of breaking 1024‑bit or 2048‑bit RSA keys, the methodology and hardware improvements it demonstrates bring those goals within a realistic timeframe.

Implications for India’s Digital Landscape

India’s economy is increasingly digital. Banking apps, online payment platforms, and government portals all rely on RSA for secure communication. The National Quantum Mission, launched in 2020, aims to position India at the forefront of quantum research, and several public and private institutions are already building quantum‑enabled infrastructures.

The recent breakthrough signals that the window for migrating to quantum‑resistant algorithms is tightening. Financial institutions such as HDFC, ICICI, and State Bank of India are already testing post‑quantum key exchange protocols. The Ministry of Electronics and Information Technology is updating guidelines to encourage the adoption of quantum‑safe standards.

Immediate Steps for Businesses and Developers

1. Audit Existing Cryptographic Practices – Identify systems that use RSA keys below 2048 bits and document the risk exposure. 2. Adopt Post‑Quantum Algorithms Early – Lattice‑based schemes such as Kyber (encryption) and Dilithium (digital signatures) are leading candidates in the NIST post‑quantum standardization process. 3. Use Hybrid Schemes – Pair classical RSA with a quantum‑resistant key exchange to provide a safety net during the transition period. 4. Engage with Standards Bodies – Follow updates from NIST, ISO, and the Indian National Standards Institute to stay aligned with best practices. 5. Train Teams – Provide workshops on quantum‑resistant cryptography for developers, security analysts, and system architects.

Looking Ahead – Post‑Quantum Cryptography in India

The National Quantum Mission has set a target of achieving a fully quantum‑secure communication network by 2030. Several Indian universities are partnering with global research groups to accelerate the development of hardware and software that can withstand quantum attacks. Companies like Tata Consultancy Services and Infosys are already investing in pilot projects that integrate quantum key distribution into existing data centers.

Public‑sector initiatives, such as the Digital India project, are expected to incorporate quantum‑safe protocols in the next major security overhaul. This will affect everything from the authentication of Aadhaar cards to the encryption of health records in the National Digital Health Mission.

The Takeaway

The successful factoring of a 768‑bit RSA key by a quantum computer is a tangible sign that the security assumptions underlying much of today’s digital infrastructure are shifting. Indian businesses, developers, and policymakers must now view quantum‑resistant cryptography not as an optional upgrade but as a necessary step toward future‑proof security. By acting now, the country can maintain trust in its digital systems while keeping pace with global technological progress.