The Department of Science and Technology (DST) of India released a landmark roadmap in early 2026 under the National Quantum Mission (NQM) to secure India’s digital networks. Chaired by Dr. Rajkumar Upadhyay, the task force recommended transitioning critical sectors like defence, banking, and telecom to quantum-safe systems to prevent future cyber threats.

Public-key cryptography, also known as asymmetric cryptography, uses a public key (which anyone can see) to encrypt messages and a private key (kept secret) to decrypt them. It forms the backbone of security protocols like HTTPS, SSL/TLS, and secure messaging services.

Shor’s Algorithm was formulated by American mathematician Peter Shor in 1994. It runs exponentially faster on quantum computers compared to classical computers, enabling them to factorize large numbers easily. This mathematically bypasses the security of current public-key encryption methods like RSA.

Symmetric cryptography (like AES) uses a single key to encrypt and decrypt data. It remains relatively safe from quantum computers because a quantum algorithm (Grover’s algorithm) only halves the security level, which can be fixed by doubling key sizes. Asymmetric cryptography (public-key), however, is highly vulnerable because Shor’s algorithm can solve its underlying math problems in minutes.

Harvest Now, Decrypt Later (HNDL) is a cyberattack strategy where adversaries collect and store encrypted data today. Although they cannot read it now, they save it with the expectation that they can decrypt it in the future using advanced quantum computers. This makes quantum security urgent even before quantum computers are fully built.

Post-Quantum Cryptography (PQC) refers to new cryptographic algorithms designed to secure data against future quantum computers. Unlike Quantum Key Distribution (QKD), which requires specialized hardware, PQC is software-based and runs on standard, existing computers and networks, making it much easier and cheaper to deploy.

In August 2024, the US National Institute of Standards and Technology (NIST) finalized its first three post-quantum standards: ML-KEM (for general encryption and key exchange), ML-DSA (for primary digital signatures), and SLH-DSA (a backup hash-based signature method). These mathematical standards are designed to withstand attacks by quantum computers.

In India, Critical Information Infrastructure (CII) is protected under Section 70 of the IT Act, 2000. It is defined as any computer resource whose destruction would severely impact national security, economy, or public health. The National Critical Information Infrastructure Protection Centre (NCIIPC) is the nodal agency that safeguards these sectors, which include power, banking, telecom, transport, and strategic enterprises.

Q-day is the hypothetical point in time when quantum computers reach the scale and stability needed to break current public-key cryptography. Experts estimate this will require a quantum computer with millions of physical qubits. While the DST report sets a target timeline around 2029, many global experts believe it may take until the mid-2030s.

Cryptographic migration is extremely difficult because encryption is rarely a single isolated tool. Instead, it is embedded deep within databases, outdated (legacy) hardware, third-party software, and identity verification protocols. Replacing vulnerable algorithms requires identifying all these interconnected dependencies, making it a massive task for organizations.

Modern cybersecurity faces a dual threat: artificial intelligence (AI) and quantum computing. Today, advanced AI algorithms can autonomously discover and exploit vulnerabilities in software code. Tomorrow, quantum computers will be able to break the mathematical foundations of encryption. Together, they expand the threat surface, requiring dynamic security solutions.

Quantum Key Distribution (QKD) is a hardware-based security method. Unlike PQC (which uses hard math), QKD uses quantum physics (like photons of light) to share secret encryption keys between two parties. If an outsider tries to intercept the key, the quantum state collapses, instantly exposing the hack. However, QKD is expensive and requires specialized fiber-optic links.

The National Quantum Mission (NQM) was approved by the Cabinet of India in April 2023 with a budget of ₹6,003 crore for 2023-2031. It aims to seed, nurture, and scale up R&D in quantum technologies. The DST Task Force report emphasizes that migrating existing infrastructure to quantum-safe architecture will require substantial additional funding and specialized human resources.

A sandbox in technology is an isolated, secure environment where software or networks can be tested without risking the main system. In policy terms, a ‘regulatory sandbox’ allows companies or government departments to test new technologies (like post-quantum algorithms) under relaxed regulatory conditions to evaluate risks, costs, and performance before full-scale deployment.

Strategic technology transitions like PQC rely on the Triple Helix Model of innovation, which emphasizes collaboration among Government (for funding, regulation, and direction), Academia (for research and training), and Industry (for commercialization and deployment). No single sector can manage the scale of quantum migration alone.