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

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

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

Method Summary

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.