Quantum security terms, checked.

A computer that uses qubits, which can hold superpositions of 0 and 1 and become entangled. For a few problems, including factoring and discrete logarithms, a large one would be far faster than any known method on ordinary computers.

For security. Today’s machines are too small and too error-prone to threaten encryption. In the Gulf, Aramco and Pasqal inaugurated a neutral-atom system that “controls 200 programmable qubits” in Dhahran in May 2026, for industrial research.^1,2

A qubit built from many physical qubits with error correction, so that it holds its state far longer than any single physical qubit. Code-breaking estimates are counted in logical qubits; headlines usually quote physical ones.

For security. The number to watch. The leading designs need about 1,200 to 1,600 logical qubits: Gidney’s 2025 design for RSA-2048 and Google’s 2026 design for 256-bit elliptic curves. Older designs needed several thousand. Quantinuum reported 48 logical qubits from 98 physical in 2025.^3,4,5

A quantum computer large and reliable enough to break the public-key cryptography in use today. Q-Day is the informal name for the day one exists.

For security. None exists in public view, and no government document we read names a year. OMB’s M-26-15 says steady advances “may yield a CRQC in the coming decade”. The US set its 2030 and 2031 deadlines on that basis.^6,7

The quantum algorithm, published in 1994, that factors large numbers and computes discrete logarithms efficiently on a large enough quantum computer.

For security. It is why RSA, Diffie-Hellman and elliptic-curve cryptography, including ECDSA signatures and Bitcoin keys, must be replaced. NIST deprecates them after 2030.⁸

A quantum search algorithm that cuts a brute-force key search to roughly the square root of the usual number of tries.

For security. Symmetric encryption survives with adequate key sizes. NIST IR 8547 keeps AES-128, AES-192 and AES-256 in its approved tables and uses them as the yardsticks for post-quantum security categories.⁸

Recording encrypted traffic or copying encrypted data today, to decrypt it once a quantum computer can recover the keys.

For security. NIST calls it “one of the main reasons” the migration is urgent, and Executive Order 14412 names it as a risk. We found no public advisory or incident report that documents a specific case. It threatens confidentiality only; signatures cannot be forged retroactively.^7,8

Ordinary software algorithms built on math problems that quantum computers are not known to solve efficiently. They run on today’s computers and networks.

For security. The fix the security agencies we read recommend first. NIST published the first three standards on August 13, 2024. “Quantum-proof” is a marketing word: the standards rest on problems with no known efficient quantum attack, which is not a proof.^9,10,11

Module-Lattice-Based Key-Encapsulation Mechanism, the NIST standard for agreeing a shared key. FIPS 203, final on August 13, 2024.

For security. NIST recommends ML-KEM-768 as the default. Through hybrid key exchange it already protects most of the human web traffic Cloudflare sees.^8,9,12

Module-Lattice-Based Digital Signature Algorithm, the NIST standard for general-purpose signatures. FIPS 204, final on August 13, 2024.

For security. Signatures can move after key exchange, because a signature cannot be recorded now and broken later. The move is still slow, because certificates and roots of trust must change across whole ecosystems. US federal high value assets and high impact systems must sign with post-quantum algorithms by December 31, 2031.^7,8,9

Stateless Hash-Based Digital Signature Algorithm. FIPS 205, final on August 13, 2024. Its security rests only on hash functions.

For security. Larger and slower than ML-DSA, kept as a conservative alternative that does not depend on lattices.⁹

FN-DSA, derived from Falcon, is a compact lattice signature planned as FIPS 206. HQC, selected on March 11, 2025, is a backup key-encapsulation method built on different math from ML-KEM.

For security. Neither had a draft standard published as of October 27, 2026. NIST said in March 2025 that it expected a final HQC standard in 2027.^8,13

Combining a classical key exchange such as X25519 with ML-KEM, so a connection stays secure if either one holds.

For security. Standardized for TLS 1.3 in RFC 10024 (August 2026) and on by default in current Chrome, Edge, Firefox and Safari, OpenSSL 3.5 and later, and OpenSSH 10. In the week to October 28, 2026, 71% of human HTTPS requests to Cloudflare used it; about 20% of origin servers Cloudflare scans support it.^12,14,15,16

A record of where an organization uses cryptography: which systems, data, keys, certificates, protocols and suppliers, and which algorithms each depends on. A cryptographic bill of materials lists the same for one product.

For security. The first duty in nearly every rule. SAMA requires procedures for identifying and classifying cryptographic assets by December 31, 2026, the phrase its Arabic text uses; the UAE standard and OMB M-26-15 require inventories; Executive Order 14412 orders CISA guidance on the minimum elements of a cryptographic bill of materials by March 19, 2027.^6,7,17,18

How we build one for a client: our post-quantum readiness assessment.

The ability to change algorithms, keys and certificates without rebuilding the systems that use them.

For security. SAMA’s circular asks institutions to assess the المرونة التشفيرية of priority assets. Its official English translation says “cryptographic resilience”; the Arabic reads closer to agility. NIST’s white paper on crypto agility, updated June 29, 2026, defines it as the capabilities needed to replace and adapt cryptographic algorithms “while preserving security and ongoing operations”.^17,19,20

The NSA’s algorithm suite for US national security systems, announced in September 2022. It names AES-256, SHA-384 or SHA-512, the hash-based LMS and XMSS for software and firmware signing, and CRYSTALS-Kyber and CRYSTALS-Dilithium at their highest level, since standardized as ML-KEM-1024 and ML-DSA-87.

For security. It governs national security systems, which Executive Order 14412 and M-26-15 exclude from their own deadlines. Contractors that build for those systems answer to it.^7,9,21

Sharing a secret key by sending single photons over fiber or free space, so that eavesdropping disturbs them. It needs special hardware and does not authenticate the other end by itself.

For security. The UK NCSC “will not support the use of QKD for government or military applications” and recommends post-quantum cryptography as the primary fix. Four European agencies say claims of unconditional security “can never apply to actual implementations”. In Qatar, Ooredoo, HBKU and the Ministry of Defense run a QKD testbed.^10,11,22

A relay site in a long-distance QKD network where the key is decrypted and re-sent. Fiber QKD reaches about one hundred kilometers before it needs one.

For security. Keys sit in the clear at each node, so every node is a physical and insider target. The European agencies conclude that end-to-end security “cannot be achieved over long distances using fibre-based QKD.”¹¹

A network that carries quantum states between devices. The UK NCSC separates three kinds: quantum replacements for classical security functions such as QKD, functions only quantum parts can provide, and networks that distribute entanglement between quantum devices such as computers or sensors.

For security. Today’s deployments are QKD links and testbeds. A network that links quantum computers is still research. Whatever the label, the parts a tester can examine are the classical ones around it: key delivery interfaces, fallback paths, management systems and the buildings that house the nodes.¹⁰

There is no quantum Wi-Fi product category. The real work is P802.11bt, an IEEE amendment project approved in September 2025 to add post-quantum algorithms to Wi-Fi security.

For security. The IEEE 802.11 Working Group says quantum computing is expected to weaken the public-key cryptography behind today’s Wi-Fi authentication and key establishment. Until 802.11bt is finished and certified, the public-key parts of Wi-Fi’s handshakes stay quantum-vulnerable.^23,24

Remote access and site links whose key exchange uses ML-KEM, usually as a hybrid with a classical method.

For security. OpenSSH has used a hybrid ML-KEM key exchange by default since version 10.0 (April 2025). VPN support varies by vendor and configuration, so it has to be checked device by device.¹⁶

Hardware that draws random numbers from a quantum process such as photon detection.

For security. No standard we read requires one. NIST’s entropy-source standard covers physical noise sources of any kind, and the UK NCSC says classical generators “have met these needs for many years, and continue to do so”. A QRNG does not make RSA or elliptic curves safe.^10,25

Three different things share the name: Google’s quantum computing lab, Google Quantum AI; research on machine learning with quantum computers; and a family of fake trading platforms.

For security. The trading platforms use deepfake celebrity videos and fake news pages to take deposits. The UK FCA, Germany’s BaFin, the Central Bank of Ireland and Australia’s National Anti-Scam Centre have warned against them. Separately, AI is already changing cryptography: in July 2026 the HAWK team withdrew its scheme from NIST’s signature process after an AI model found a mathematical flaw in it.^{26,27,28,29,30}