org.bouncycastle.crypto.kems

Class SM9KEMGenerator

java.lang.Object

org.bouncycastle.crypto.kems.SM9KEMGenerator

All Implemented Interfaces:

EncapsulatedSecretGenerator

public class SM9KEMGenerator
extends java.lang.Object
implements EncapsulatedSecretGenerator

SM9 key encapsulation mechanism - encapsulation side (GM/T 0044.4-2016, clause 6). Given a recipient identity and the encryption master public key, produces a shared key K and its encapsulation C = [r]Q_B (a G1 point, encoded x||y).

Usage warning: an identity's encryption key should be used for this mechanism or for public-key encryption (SM9Engine), but not for both. A deployment needing both has its KGC publish a separate hid for each function, as it already does for the key exchange, so that the two keys are distinct.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ENCAPSULATION_LENGTH The length in bytes of an SM9 KEM encapsulation: C = [r]Q_B, a G1 point written as x || y.

Constructor Summary

Constructors

Constructor and Description
SM9KEMGenerator(int keyLenBits, java.security.SecureRandom random)

Method Summary

Modifier and Type	Method and Description
SecretWithEncapsulation	generateEncapsulated(AsymmetricKeyParameter recipientKey) Generate secret/encapsulation based on the recipient public key.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ENCAPSULATION_LENGTH

public static final int ENCAPSULATION_LENGTH

The length in bytes of an SM9 KEM encapsulation: C = [r]Q_B, a G1 point written as x || y. The one value both the generator's and the extractor's sides report, so the two cannot drift.

See Also:

Constant Field Values

Constructor Detail

SM9KEMGenerator

public SM9KEMGenerator(int keyLenBits,
                       java.security.SecureRandom random)

Method Detail

generateEncapsulated

public SecretWithEncapsulation generateEncapsulated(AsymmetricKeyParameter recipientKey)

Description copied from interface: EncapsulatedSecretGenerator

Generate secret/encapsulation based on the recipient public key.

Specified by:

generateEncapsulated in interface EncapsulatedSecretGenerator

Returns:

An SecretWithEncapsulation derived from the recipient public key.