GM/T 0081-2020SM9 cryptographic algorithm encryption and signature message syntax specification (English PDF)

1 Scope

This Document defines the encryption and signature message syntax using the SM9 cryptographic algorithm.

This Document is applicable to the standardized encapsulation of operation results when the SM9 algorithm is used for encryption and signature operations.

2 Normative References

The following documents are essential to the application of this Document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) is applicable to this Document.

GB/T 33560 Information Security Technology - Cryptographic Application Identifier Criterion Specification GB/T 38635 (all parts) Information Security Technology - Identity-Based Cryptographic Algorithms SM9 GM/T 0080 SM9 Cryptographic Algorithm Application Specification GM/Z 4001-2013 Cryptographic Terms

3 Terms and Definitions

For the purposes of this Document, the terms given in GB/T 38635 (all parts) and GM/Z 4001-2013 and the following apply.

4 Abbreviations

The following abbreviations are applicable to this Document.

IBC: Identity-Based Cryptography.

IRIs: Internationalized Resource Identifiers.

IRL: Identifier Revocation List.

KGC: Key Generation Centre.

OID: Object Identifier.

Where:

The version item (version) determines the version of the IBCSysParams format. The format mentioned in this document shall be set to 2.

The name item (districtName) is an IA5 string that shall be encoded with URI or IRI.

districtSerial represents an integer that can be set by the only available IBC public parameter (for URI or IRI defined by districtName). If a new parameter is announced for districtName, the value of districtSerial shall be greater than the value of districtSerial used before.

The validity period item (validity) determines the life of a specific IBCSysParams example and is determined according to the following:

The values of notBefore and notAfter must be expressed in Greenwich Mean Time and include seconds (for example, the time is expressed as YYYYMMDDHHMMSSZ).

Even if the number of seconds is zero, it must be expressed as the nearest number of seconds. The customer must confirm that the date of the IBC public parameter it uses is between the notBefore time and the notAfter time of the IBC public parameter. At the same time, if the date is not in this interval, the parameter used for IBC encryption operation cannot be used.

When the value of IbcPublicParameters, IbcIdentityType or IbcParamExtensions changes an area, the IBC public parameters shall be regenerated and announced. The customer shall retrieve the IBC public parameters within the application configuration interval to ensure the version of the parameters is latest.

The IBCPublicParameters public parameter item is a structure that contains public parameters (corresponding to the IBC algorithm formula supported by PKG). It is defined as follows:

Where:

ibcAlgorithm OID determines the IBC algorithm formula. Two IBC algorithmic OIDs and their publicParameterData structures.

publicParameterData is a DER encoding structure of SM9PublicParameterData, which contains the real encrypted parameters. Its specific structure is as follows: