Cryptography terms, explained.
The words this industry uses for quantum risk, standards, visibility and hardware, each in plain language.
Quantum risk
Post-quantum cryptography
Also called PQC, quantum-safe encryption, quantum-resistant cryptography
Encryption and signature methods designed to stay secure against quantum computers as well as today’s computers. NIST published its first three standards for them in 2024 and says organizations should begin applying them now.
Why plan for quantum-safe encryption nowSource: NIST (opens csrc.nist.gov)
Q-Day
Also called Y2Q
The day a quantum computer can break the public-key encryption most systems rely on today. Nobody can honestly give it a date, and the G7’s financial cyber experts describe the path of quantum computing as uncertain. Preparing takes years either way.
What is a quantum computer?Source: G7 Cyber Expert Group (opens home.treasury.gov)
Harvest now, decrypt later
Also called HNDL, store now, decrypt later, data stolen today, decrypted later
Capturing encrypted data today to decrypt it once a capable quantum computer exists. It is a risk to confidentiality, and it makes data that must stay private for years a present concern.
Which of your data it affectsSource: G7 Cyber Expert Group (opens home.treasury.gov)
Trust now, forge later
Also called TNFL, signatures trusted today, forged later
Forging digital signatures once the method behind them can be broken, so software updates, certificates or signed records that systems still trust could be faked. It is a risk to integrity. The longer something must stay trusted, the earlier its signatures need a plan.
Quantum readiness
Also called post-quantum readiness, quantum-safe readiness
How prepared an organization is to move to quantum-safe encryption: knowing where it relies on cryptography, what to change first, and how to change it safely. IBM’s quantum-safe readiness index averaged 25 out of 100 in 2025.
Source: IBM Institute for Business Value (opens www.ibm.com)
Quantum-proof
Also called quantum-secure
A marketing term worth treating with care. No method is proof against every future attack. Quantum-safe is the more accurate word: designed to resist known quantum attacks, with published standards behind it.
Standards and deadlines
NIST’s post-quantum standards
Also called FIPS 203, FIPS 204, FIPS 205, ML-KEM, ML-DSA, SLH-DSA
The first three quantum-safe standards, published by NIST in August 2024: ML-KEM (FIPS 203) for agreeing encryption keys, and ML-DSA (FIPS 204) and SLH-DSA (FIPS 205) for digital signatures.
NIST IR 8547
Also called the 2030 and 2035 deadlines
NIST’s draft plan for the move to quantum-safe cryptography. It proposes deprecating RSA and elliptic-curve methods after 2030 and disallowing them after 2035. The draft is still open.
Does quantum computing break all encryption?Source: NIST (opens csrc.nist.gov)
Executive Order 14412
Also called the US quantum executive order, Securing the Nation Against Advanced Cryptographic Attacks
A June 2026 US executive order that moves high-value federal systems to quantum-safe key exchange by December 31, 2030, and to quantum-safe digital signatures by the end of 2031.
A deadline isn’t a migration planSource: The White House (opens www.whitehouse.gov)
G7 quantum roadmap
Also called G7 Cyber Expert Group roadmap
Non-binding guidance from the G7’s financial cyber experts that targets critical financial systems between 2030 and 2032, and the whole financial sector by 2035.
India’s quantum-safe roadmap
Also called Roadmap to Quantum Resiliency, DST quantum-safe roadmap, India PQC migration timeline
India’s national plan for moving to quantum-safe encryption, published in May 2026 by the Department of Science and Technology under the National Quantum Mission. It recommends that critical sectors finish by 31 December 2029 and other enterprises by 31 December 2033.
What India’s roadmap asks of your teamsSource: Department of Science and Technology, Government of India (National Quantum Mission) (opens dst.gov.in)
National Quantum Mission
Also called NQM
India’s government programme for quantum technologies, run by the Department of Science and Technology. A task force set up under it wrote the country’s quantum-safe roadmap.
Critical information infrastructure
Also called CII
Systems whose failure would seriously harm national security, the economy or public safety. India’s quantum-safe roadmap names government, strategic and defence systems, power, telecoms, transport, and banking, financial services and insurance, and asks them to move first.
The milestones for critical sectorsSource: Department of Science and Technology, Government of India (National Quantum Mission) (opens dst.gov.in)
CNSA 2.0
Also called Commercial National Security Algorithm Suite 2.0
The NSA’s quantum-safe algorithm requirements for US national security systems. It applies to those systems specifically, not to every federal contract or private company.
FIPS 140-3
Also called cryptographic module validation
The US and Canadian standard for testing cryptographic modules such as HSMs. Arcrix™ HSM is designed so the finished product can be submitted for this testing. It is not certified today.
Cryptographic agility
Also called crypto agility, crypto-agility
Being able to replace cryptographic methods across protocols, applications, hardware and infrastructure while keeping systems secure and running. NIST sets out how to achieve it in CSWP 39, updated in June 2026. In plain words: changing cryptography quickly and safely.
Visibility and inventory
Cryptographic inventory
Also called cryptographic discovery
A record of where your business uses keys, certificates and algorithms, built by scanning systems. It’s where a quantum-safe programme starts, though a list alone doesn’t say what to change first.
CBOM
Also called cryptographic bill of materials, cryptography bill of materials
A structured record of the cryptography in use, where, and for what, in a form other tools can read. Arcrix™ Platform exports one, signed, with its gaps declared.
PKI
Also called public key infrastructure
The certificates, and the authorities that issue them, that let systems and people trust each other online. Its root certificates are often the longest part of a quantum-safe move.
Why your most trusted certificate may be your longest project
Certificate lifecycle management
Also called CLM
Tools that issue, renew and revoke certificates on schedule. Arcrix™ works alongside them and adds an independent check on whether a change removed a weakness.
Machine identity
Also called non-human identity, workload identity
The certificates and keys that let services, devices and workloads prove who they are to each other. Each one needs an owner who can change it.
Cryptographic posture management
Also called cryptographic posture
An industry term for keeping a continuous, prioritized view of the cryptography an organization uses, its weaknesses, and whether it meets policy.
Change and evidence
Cryptographic risk
The chance that a key, certificate or algorithm your systems depend on can be broken, misused, or found to fall short of a rule you must meet.
Remediation
Also called cryptographic remediation
Changing cryptography to remove a weakness, such as replacing a weak key. A fix counts when fresh evidence shows the weakness is gone.
Hybrid cryptography
Also called hybrid key exchange, hybrid mode
Running a quantum-safe method alongside a traditional one during the move, so systems stay compatible while protection improves. NIST describes hybrid mechanisms as one way to manage the transition.
Hardware
HSM
Also called hardware security module
Secure hardware that protects encryption keys and carries out cryptographic operations inside a protected boundary. Most were designed around a fixed set of methods, meant to last the life of the device.
KMS
Also called key management service, key management
A service, often run by a cloud provider, that stores encryption keys and controls who can use them.
Entropy
Also called randomness, random number generation
The unpredictability behind every key. A key is only as strong as the randomness used to make it.