Post-Quantum, PQC, Quantum Security

PostQuantum.com – Industry news and blog on Quantum Computing, Quantum Security, PQC, Post-Quantum, AI Security

  • QKD BB84

    Quantum Key Distribution (QKD) and the BB84 Protocol

    Quantum Key Distribution (QKD) represents a radical advancement in secure communication, utilizing principles from quantum mechanics to distribute cryptographic keys with guaranteed security.Unlike classical encryption, whose security often relies on the computational difficulty of certain mathematical problems, QKD's security is based on the laws of physics, which are, as far…

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  • Quantum Computing Security

    The Quantum Computing Threat

    The secret sauce of quantum computing, which even Einstein called "spooky," is the ability to generate and manipulate quantum bits of data or qubits. Certain computational tasks can be executed exponentially faster on a quantum processor using qubits, than on a classical computer with 1s and 0s. A qubit can…

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  • ITU Y 3800

    Inside ITU’s New Quantum Key Standard (Y.3800)

    In late 2019, the International Telecommunication Union (ITU) quietly reached a milestone in cybersecurity: it approved a new standard that could redefine how we secure data in the coming quantum era. The standard, known as ITU-T Recommendation Y.3800, is an “Overview on networks supporting Quantum Key Distribution” - essentially a…

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  • PQC Upgrade Challenges

    Challenges of Upgrading to Post-Quantum Cryptography (PQC)

    The shift to post-quantum cryptography is not a distant problem but an imminent challenge that requires immediate attention. The quantum threat affects all forms of computing—whether it’s enterprise IT, IoT devices, or personal electronics. Transitioning to quantum-resistant algorithms is a complex, resource-intensive task that demands coordination across the supply chain,…

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  • Mosca's Theorem

    Mosca’s Theorem and Post‑Quantum Readiness: A Guide for CISOs

    Mosca’s Theorem is a risk framework formulated to help organizations gauge how urgent their post-quantum preparations should be. It is often summarized by the inequality X + Y > Q, where: X = the length of time your data must remain secure (the required confidentiality lifespan of the information). Y…

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  • Q-Day Y2Q Y2K

    Q-Day (Y2Q) vs. Y2K

    In the late 1990s, organizations worldwide poured time and money into exorcising the “millennium bug.” Y2K remediation was a global scramble. That massive effort succeeded: when January 1, 2000 hit, planes didn’t fall from the sky and power grids stayed lit. Ever since, Y2K has been held up as both…

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  • Quantum Computing Introduction

    What’s the Deal with Quantum Computing: Simple Introduction

    Quantum computing holds the potential to revolutionize fields where classical computers struggle, particularly in areas involving complex quantum systems, large-scale optimization, and cryptography. The power of quantum computing lies in its ability to leverage the principles of quantum mechanics—superposition and entanglement—to perform certain types of calculations much more efficiently than…

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  • Quantum Random Number Generation QRNG

    Introduction to Quantum Random Number Generation (QRNG)

    Cryptographic systems rely on the unpredictability and randomness of numbers to secure data. In cryptography, the strength of encryption keys depends on their unpredictability. Unpredictable and truly random numbers—those that remain secure even against extensive computational resources and are completely unknown to adversaries—are among the most essential elements in cryptography…

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  • Sign Today, Forge Tomorrow STFT Trust Now, Forge Later TNFL

    Sign Today, Forge Tomorrow (STFT) or Trust Now, Forge Later (TNFL) Risk

    Sign Today, Forge Tomorrow (STFT) or Trust Now, Forge Later (TNFL) is the digital‑signature equivalent of HNDL. Digital signatures underpin everything from software updates and firmware integrity to identity verification and supply‑chain provenance. Today’s signatures are based on RSA or ECDSA, which quantum computers will also break. When that happens,…

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  • CRQC Quantum Prediction RSA 2048

    The CRQC Quantum Capability Framework

    This guide is a detailed, end‑to‑end map for understanding what it will actually take to reach a cryptographically relevant quantum computer (CRQC), i.e. break RSA-2048 - not just headline qubit counts. A CRQC must meet two conditions: the algorithmic requirements of the target attack and the hardware capabilities needed to…

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  • IT OT Asset Discovery Challenges

    The Challenge of IT and OT Asset Discovery

    Every CISO understands the simple truth: you can’t protect what you don’t know you have. A comprehensive inventory of IT and OT assets - from servers and laptops to industrial controllers and IoT sensors - is the foundation of effective cybersecurity. In theory, building this asset inventory sounds straightforward. In…

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  • BHT PQC Quantum

    Brassard–Høyer–Tapp (BHT) Quantum Collision Algorithm and Post-Quantum Security

    The Brassard–Høyer–Tapp (BHT) algorithm is a quantum algorithm discovered in 1997 that finds collisions in hash functions faster than classical methods. In cryptography, a collision means finding two different inputs that produce the same hash output, undermining the hash’s collision resistance. The BHT algorithm theoretically reduces the time complexity of…

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  • Quantum CRQC Q-Day Capability Continuous Operation

    Capability D.3: Continuous Operation (Long-Duration Stability)

    One of the most critical requirements for a cryptographically relevant quantum computer (CRQC) is continuous operation - the ability to run a complex quantum algorithm non-stop for an extended period (on the order of days) without losing quantum coherence or needing a reset. In practical terms, the entire quantum computing…

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  • Quantum CRQC Q-Day Capability Algorithm

    Capability D.1: Full Fault-Tolerant Algorithm Integration

    Imagine a quantum computer that can execute an entire algorithm start-to-finish with errors actively corrected throughout. Full fault-tolerant algorithm integration is exactly that: the orchestration of all components - stable logical qubits, high-fidelity gates, error-correction cycles, ancilla factories, measurements, and real-time feedback - to run a useful quantum algorithm reliably…

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  • Quantum CRQC Q-Day Capability Decoder

    Capability D.2: Decoder Performance (Real‑Time Error Correction Processing)

    In a fault-tolerant quantum computer, qubits are continuously monitored via stabilizer measurements (producing “syndrome” bits) to detect errors. The decoder is a classical algorithm (running on specialized hardware) that takes this rapid stream of syndrome data and figures out which qubits have experienced errors, so that corrections can be applied…

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