• Cybersecurity Glossary
What is Quantum Computing?
Quantum Computing is a computing paradigm that leverages quantum mechanical phenomena, including superposition and entanglement, to process information using qubits instead of classical bits. While a classical bit is limited to 0 or 1, a qubit can represent both states simultaneously, enabling quantum computers to solve certain mathematical problems exponentially faster than any classical machine. This capability has profound implications for cryptography and network security: a sufficiently powerful quantum computer could break the public key encryption that protects virtually all digital communications today, from banking transactions to SD-WAN tunnels. With expert timelines shortening and NIST mandating migration to post quantum algorithms by 2030, preparing enterprise networks for the quantum era is no longer optional.
Quantum Computing definition
Quantum Computing is a type of computation that harnesses quantum mechanical phenomena to process information in fundamentally different ways from classical computers. Classical computers encode information in bits, each of which is definitively either 0 or 1. Quantum computers use quantum bits, or qubits, which can exist in a superposition of both 0 and 1 simultaneously. This seemingly small difference has enormous consequences.
A classical computer with n bits can be in exactly one of 2^n possible states at any given moment. A quantum computer with n qubits can represent all 2^n states at the same time through superposition. When qubits are entangled, operations on one qubit instantly affect the others, enabling a form of massive parallelism that has no classical equivalent.
The practical result is that quantum computers can solve certain categories of problems, particularly those involving factoring large numbers, searching unsorted databases, and simulating quantum systems, exponentially faster than classical machines. The most significant implication for enterprise IT and cybersecurity is that the mathematical problems on which modern public key cryptography depends (integer factorization for RSA, discrete logarithms for Diffie Hellman, and elliptic curve problems for ECC) are precisely the types of problems that quantum computers can solve efficiently.
Key principles: qubits, superposition, and entanglement
Understanding quantum computing requires grasping several core concepts from quantum mechanics that have no direct analog in classical computing. These principles are not theoretical abstractions; they are the physical foundations on which quantum hardware operates and quantum algorithms achieve their performance advantages:
From physics to cybersecurity threat: The combination of superposition and entanglement enables algorithms like Shor’s (for factoring integers) and Grover’s (for searching unsorted data) that are exponentially or quadratically faster than their classical equivalents. Shor’s algorithm is the primary reason quantum computing poses a direct threat to public key cryptography. It can factor the large numbers that make RSA secure and compute the discrete logarithms that protect Diffie Hellman and ECC key exchanges, potentially breaking the encryption that secures virtually all digital communications.
Quantum vs classical computing
Quantum and classical computing are not competitors for the same tasks. They are fundamentally different computing paradigms, each suited to different problem types. Understanding their differences helps clarify where the quantum threat to cybersecurity originates:
| Dimension | Classical Computing | Quantum Computing |
|---|---|---|
| Information unit | Bit (0 or 1) | Qubit (0, 1, or both simultaneously) |
| Processing model | Sequential or parallel logic gates | Quantum gates exploiting superposition and entanglement |
| Speed advantage | Fast for general purpose tasks | Exponentially faster for specific problems (factoring, optimization, simulation) |
| Error handling | Mature, low error rates | High error rates requiring quantum error correction |
| Current maturity | Fully mature, billions of devices deployed | Early stage, hundreds to thousands of qubits |
| Cryptographic impact | Basis of current encryption systems | Can break RSA, ECC, and other public key cryptosystems via Shor’s algorithm |
| Best suited for | General computing, business applications, AI training | Cryptanalysis, molecular simulation, optimization problems, quantum chemistry |
| Energy and environment | Standard operating conditions | Requires near absolute zero temperatures and electromagnetic isolation |
Why this matters for network security: Classical computers cannot factor a 2048 bit RSA key in any practical timeframe; it would take trillions of years. A quantum computer with enough stable qubits running Shor’s algorithm could do it in hours. This is not a theoretical possibility: the algorithm exists, and quantum hardware is advancing toward the scale needed to execute it. The only question is when, not if.
Impact on cryptography and network security
The relationship between quantum computing and cryptography is direct and well understood. Modern public key cryptography relies on the computational difficulty of specific mathematical problems. Quantum computers can solve these problems efficiently, which means they can break the cryptographic systems that protect digital communications:
RSA and integer factorization
RSA encryption relies on the difficulty of factoring the product of two large prime numbers. A 2048 bit RSA key is considered unbreakable by classical computers. Shor’s algorithm on a quantum computer could factor this key in hours. Once factored, an attacker can derive the private key and decrypt all data encrypted with the corresponding public key.
Diffie Hellman and discrete logarithms
The Diffie Hellman key exchange, used in TLS, IPsec, and virtually every VPN and SD-WAN implementation, relies on the difficulty of the discrete logarithm problem. Shor’s algorithm solves discrete logarithms as efficiently as it factors integers, meaning the key exchange mechanism that establishes secure sessions between network devices would be broken.
Elliptic Curve Cryptography (ECC)
ECC is widely used because it offers equivalent security to RSA with much smaller key sizes. However, it is equally vulnerable to quantum attack. The elliptic curve discrete logarithm problem that protects ECC can be solved by a variant of Shor’s algorithm. Recent research from Google has revised down the qubit requirements for breaking 256 bit elliptic curves, suggesting practical attacks may arrive sooner than previously estimated.
Symmetric encryption: a different story
Symmetric algorithms like AES are less vulnerable. Grover’s algorithm provides a quadratic speedup for brute force attacks, effectively halving the key length. AES 256 remains considered quantum safe because it retains 128 bit equivalent security against a quantum attacker, which is sufficient. The primary threat is to public key cryptography, not symmetric encryption.
Quantum threats to enterprise networks
The quantum threat is not abstract or distant. It has concrete implications for enterprise network infrastructure, and some aspects of the threat are already active today:
The urgency of preparation: Mosca’s theorem provides a framework for assessing migration urgency. If the time needed to migrate your systems (X) plus the time your data must remain confidential (Y) exceeds the time until a cryptographically relevant quantum computer exists (Z), then migration is already overdue. For many organizations handling long lived sensitive data over SD-WAN networks, this calculation suggests that the transition to quantum safe cryptography should begin now.
Post Quantum Cryptography and NIST standards
Post Quantum Cryptography (PQC) is the field of developing cryptographic algorithms that are secure against attacks from both classical and quantum computers. Unlike quantum cryptography (which requires quantum hardware), PQC algorithms run on classical computers and can be deployed on existing network infrastructure. The transition to PQC is the primary defense against the quantum threat:
The migration imperative: The U.S. government has mandated federal agencies to begin migrating to PQC, with RSA and ECDSA scheduled for deprecation by 2030 and full disallowance by 2035. CISA recommends that all organizations start with a cryptographic inventory to identify where quantum vulnerable algorithms are used, then develop a migration roadmap that prioritizes systems protecting long lived sensitive data. For enterprise WAN infrastructure, SD-WAN platforms with built in crypto agility and PQC support simplify this transition significantly.
Teldat Quantum SD-WAN solutions
Teldat has developed a structured roadmap to evolve its SD-WAN architecture toward a quantum safe model, designed to protect enterprise WAN traffic against both current and future quantum enabled attacks. The roadmap is built on three technological pillars, each addressing a different phase of the quantum threat timeline:
The Teldat quantum advantage: As a network hardware manufacturer and cybersecurity provider, Teldat delivers quantum safe SD-WAN capabilities from a unified ecosystem. PS PPK for immediate protection, ML KEM for standards based quantum resistance, QKD for future proof key generation, embedded NGFW for defense in depth, and CNM for centralized management are all integrated into a single platform. This means organizations can begin their quantum transition today without replacing their network infrastructure or managing multiple vendor solutions.
Frequently asked questions about Quantum Computing – (FAQ’s)
❯ What is Quantum Computing in simple terms?
Quantum Computing is a type of computing that uses quantum mechanical phenomena such as superposition and entanglement to process information. Instead of classical bits that are either 0 or 1, quantum computers use qubits that can represent both states simultaneously, allowing them to solve certain complex problems exponentially faster than classical computers.
❯ How does Quantum Computing threaten current encryption?
Quantum computers running Shor’s algorithm could efficiently factor large numbers and compute discrete logarithms, breaking widely used public key cryptosystems like RSA and Elliptic Curve Cryptography. This means encrypted data protected by these algorithms today could be decrypted by a sufficiently powerful quantum computer in the future.
❯ What is the harvest now, decrypt later threat?
Harvest now, decrypt later is an attack strategy where adversaries capture and store encrypted data today with the intention of decrypting it in the future when quantum computers become powerful enough. This is particularly dangerous for data that must remain confidential for years or decades, such as government secrets, medical records, and financial transactions.
❯ What is Post Quantum Cryptography?
Post Quantum Cryptography (PQC) refers to cryptographic algorithms designed to be secure against attacks from both classical and quantum computers. These algorithms are based on mathematical problems that quantum computers cannot solve efficiently, such as lattice based problems, hash based signatures, and code based schemes. NIST finalized the first PQC standards in 2024.
❯ Is Quantum Computing a threat to SD-WAN networks?
Yes. SD-WAN networks rely heavily on IPsec encrypted tunnels using public key cryptography for key exchange. A quantum computer could break these key exchange mechanisms, exposing all traffic flowing through SD-WAN tunnels. Organizations must begin transitioning to quantum safe SD-WAN architectures that use post quantum key exchange and pre shared post quantum keys.
❯ How does Teldat protect against quantum threats?
Teldat has implemented a Quantum SD-WAN roadmap based on three pillars: PS PPK (Pre Shared Post Quantum Keys) for immediate protection against harvest now decrypt later attacks, ML KEM integration for NIST standardized post quantum key exchange, and QKD (Quantum Key Distribution) compatibility for future quantum safe key generation. These capabilities are built into Teldat SD-WAN infrastructure managed through CNM.
Prepare your network for the Quantum Era with Teldat
From PS PPK for immediate harvest now decrypt later protection to ML KEM for NIST standardized post quantum key exchange, Teldat Quantum SD-WAN delivers quantum safe network security from a single integrated platform.
