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private key

nounverified·updated May 9, 2026

A cryptographic key, used with a public key cryptographic algorithm, that is uniquely associated with an entity and is not made public. In an asymmetric (public) cryptosystem, the private key is associated with a public key. Depending on the algorithm, the private key may be used, for example, to: 1) Compute the corresponding public key, 2) Compute a digital signature that may be verified by the corresponding public key, 3) Decrypt keys that were encrypted by the corresponding public key, or 4) Compute a shared secret during a key-agreement transaction.

polysemousMWENISTIR 7298: Glossary of Key Information Security Terms, Revision 2

Senses

National Initiative for Cybersecurity Careers and Studies (NICCS) Cybersecurity Lexiconextended definition available

A cryptographic key that must be kept confidential and is used to enable the operation of an asymmetric (public key) cryptographic algorithm.

NISTIR 7298: Glossary of Key Information Security Terms, Revision 2

The secret part of an asymmetric key pair that is typically used to digitally sign or decrypt data.

NISTIR 7298: Glossary of Key Information Security Terms, Revision 2sense 3 pending review

A cryptographic key used with a public key cryptographic algorithm, which is uniquely associated with an entity, and not made public; it is used to generate a digital signature; this key is mathematically linked with a corresponding public key.

NISTIR 7298: Glossary of Key Information Security Terms, Revision 2sense 4 pending review

A cryptographic key, used with a public key cryptographic algorithm, that is uniquely associated with an entity and is not made public.

NISTIR 7298: Glossary of Key Information Security Terms, Revision 2sense 5 pending review

In an asymmetric cryptography scheme, the private or secret key of a key pair which must be kept confidential and is used to decrypt messages encrypted with the public key or to digitally sign messages, which can then be validated with the public key.

NIST SP 800-171r3attested usage pack match

No definition is given in NIST SP 800-171r3. The term is attested in use at 1 citation in that document; a definition is pending curation.

Classifications

Entity Type

Credential90%rule-basedr:entity.credential.cert.v1
?unassignedlast reviewed

Sensitivity

unclassified

Information Class

unclassified

Variants

plural
private keys
possessive
private key's
pluralpossessive
private keys'