PQC concepts
What is KEM?
Also known as Key Encapsulation Mechanism.
A primitive that establishes a shared symmetric key between two parties without traditional public-key encryption. ML-KEM, HQC, BIKE, FrodoKEM, McEliece are all KEMs. Used to wrap AES-256-GCM data keys in QNSI vault + KMS.
Decision context
Why KEM matters
A key encapsulation mechanism establishes a shared secret that can feed symmetric encryption and authenticated protocol keys. Security depends on correct decapsulation, ciphertext validation, key derivation, authentication and protocol binding; the KEM does not by itself authenticate the peer or encrypt bulk data.
How to evaluate KEM
Trace key generation, encapsulation, decapsulation, KDF input and authenticated-encryption use end to end. Test invalid and modified ciphertexts, key mismatch, replay boundaries and zeroization. Confirm the algorithm identifier is bound to the operation so downgrade cannot silently select a classical alternative.
PQC concepts
PQC concepts evidence boundary
Post-quantum programmes combine cryptography, architecture, data lifetime, operational ownership, and migration governance. A concept is useful only when it changes a concrete inventory, policy, design, test, or evidence decision. Treat terminology as a decision aid rather than proof that a control exists.
FAQ
Common questions
What is KEM?
A primitive that establishes a shared symmetric key between two parties without traditional public-key encryption. ML-KEM, HQC, BIKE, FrodoKEM, McEliece are all KEMs. Used to wrap AES-256-GCM data keys in QNSI vault + KMS.
Why does KEM matter?
A key encapsulation mechanism establishes a shared secret that can feed symmetric encryption and authenticated protocol keys. Security depends on correct decapsulation, ciphertext validation, key derivation, authentication and protocol binding; the KEM does not by itself authenticate the peer or encrypt bulk data.
How should KEM be evaluated?
Trace key generation, encapsulation, decapsulation, KDF input and authenticated-encryption use end to end. Test invalid and modified ciphertexts, key mismatch, replay boundaries and zeroization. Confirm the algorithm identifier is bound to the operation so downgrade cannot silently select a classical alternative.
What is KEM also known as?
KEM is also known as Key Encapsulation Mechanism. A primitive that establishes a shared symmetric key between two parties without traditional public-key encryption. ML-KEM, HQC, BIKE, FrodoKEM, McEliece are all KEMs. Used to wrap AES-256-GCM data keys in QNSI vault + KMS.
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