A
cryptographic
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adver ...
key is called ephemeral if it is generated for each execution of a key establishment process.
In some cases ephemeral keys are used more than once, within a single session (e.g., in broadcast applications) where the sender generates only one ephemeral key pair per message and the
private key
Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...
is combined separately with each recipient's
public key
Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic a ...
. Contrast with a
static key A cryptographic key is called static if it is intended for use for a relatively long period of time and is typically intended for use in many instances of a cryptographic key establishment scheme. Contrast with an ephemeral key.
See also
* Cryptogr ...
.
Private / public ephemeral key agreement key
Private (resp. public) ephemeral key agreement keys are the private (resp. public) keys of asymmetric key pairs that are used a single key establishment transaction to establish one or more keys (e.g., key wrapping keys, data encryption keys, or
MAC
Mac or MAC most commonly refers to:
* Mac (computer), a family of personal computers made by Apple Inc.
* Mackintosh, a raincoat made of rubberized cloth
* A variant of the word macaroni, mostly used in the name of the dish mac and cheese
* Mac, ...
keys) and, optionally, other keying material (e.g.,
initialization vector
In cryptography, an initialization vector (IV) or starting variable (SV) is an input to a cryptographic primitive being used to provide the initial state. The IV is typically required to be random or pseudorandom, but sometimes an IV only needs to ...
s).
See also
*
Cryptographic key types A cryptographic key is a string of data that is used to lock or unlock cryptographic functions, including authentication, authorization and encryption. Cryptographic keys are grouped into cryptographic key types according to the functions they ...
*
Session key
A session key is a single-use symmetric key used for encrypting all messages in one communication session. A closely related term is content encryption key (CEK), traffic encryption key (TEK), or multicast key which refers to any key used for e ...
External links
* ''Recommendation for Key Management — Part 1: General,'
NIST Special Publication 800-57NIST ''Cryptographic Toolkit''
References
Key management
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