ISO 11568-4:2007 バンキング—キー管理（小売）—パート4：非対称暗号システム—キー管理とライフサイクル | ページ 6

3.1

asymmetric cipher

cipher in which the encipherment key and the decipherment key are different, and in which it is computationally infeasible to deduce the (private) decipherment key from the (public) encipherment key

3.2

asymmetric cryptosystem

cryptosystem consisting of two complementary operations each utilizing one of two distinct but related keys, the public key and the private key, having the property that it is computationally infeasible to determine the private key from the public key

3.3

asymmetric key pair generator

secure cryptographic device used for the generation of asymmetric cryptographic keys

3.4

certificate

credentials of an entity, signed using the private key of the certification authority which issued it, and thereby rendered unforgeable

3.5

certification authority

ca

entity trusted by one or more entities to create, assign and revoke or hold public key certificates

Note 1 to entry: Optionally the certification authority can create and assign keys to the entities.

3.6

communicating party

party that sends or receives the public key for the communication with the party that owns the public key

3.7

computationally infeasible

property that a computation is theoretically achievable but is not feasible in terms of the time or resources required to perform it

3.8

credentials

identification data for an entity, incorporating at a minimum the entity's distinguished name and public key

Note 1 to entry: Additional data can be included.

3.9

cryptoperiod

time span during which a specific key is authorized for use or in which the keys for a given system may remain in effect

3.10

digital signature system

asymmetric cryptosystem that provides for the creation and subsequent verification of digital signatures

3.11

hash function

one-way function that maps a set of strings of arbitrary length on to a set of fixed-length strings of bits

Note 1 to entry: A collision-resistant hash function is one with the property that it is computationally infeasible to construct distinct inputs that map to the same output.

3.12

independent communication

process that allows an entity to counter-verify the correctness of a credential and identification documents prior to producing a certificate (e.g., call-back, visual identification, etc.)

3.13

key agreement

process of establishing a shared secret key between entities in such a way that neither of them can predetermine the value of that key

3.14

key share

one of at least two parameters related to a cryptographic key generated in such a way that a quorum of such parameters can be combined to form the cryptographic key but such that fewer than a quorum provide no information about the key

3.15

non-repudiation of origin

property that the originator of a message and associated cryptographic check value (i.e., digital signature) is not able to subsequently deny, with an accepted level of credibility, having originated the message