Package com.google.crypto.tink.hybrid.internal

Interface HpkeKem

  • @Immutable
public interface HpkeKem
    Interface for Hybrid Public Key Encryption (HPKE) key encapsulation mechanism (KEM).

    HPKE RFC is available at https://www.rfc-editor.org/rfc/rfc9180.html.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      byte[] authDecapsulate​(byte[] encapsulatedKey, HpkeKemPrivateKey recipientPrivateKey, byte[] senderPublicKey)
      Extracts the shared secret from encapsulatedKey using recipientPrivateKey.
      com.google.crypto.tink.hybrid.internal.HpkeKemEncapOutput authEncapsulate​(byte[] recipientPublicKey, HpkeKemPrivateKey senderPrivateKey)
      Similar to encapsulate(byte[]), but the output additionally encodes an assurance that the KEM shared secret was generated by the holder of senderPrivateKey.
      byte[] decapsulate​(byte[] encapsulatedKey, HpkeKemPrivateKey recipientPrivateKey)
      Extracts the shared secret from encapsulatedKey using recipientPrivateKey.
      com.google.crypto.tink.hybrid.internal.HpkeKemEncapOutput encapsulate​(byte[] recipientPublicKey)
      Generates and encapsulates a shared secret using the recipientPublicKey.
      byte[] getKemId()
      Returns the HPKE KEM algorithm identifier for the underlying KEM implementation.

    • Method Detail

      • encapsulate

        com.google.crypto.tink.hybrid.internal.HpkeKemEncapOutput encapsulate​(byte[] recipientPublicKey)
                                                               throws java.security.GeneralSecurityException
        Generates and encapsulates a shared secret using the recipientPublicKey. Returns a HpkeKemEncapOutput object that contains the raw shared secret and the encapsulated key. The HPKE RFC refers to this method as Encap(), which is used by the sender.
        Throws:
        java.security.GeneralSecurityException - when either the shared secret cannot be generated or the shared secret cannot be encapsulated.

      • decapsulate

        byte[] decapsulate​(byte[] encapsulatedKey,
                   HpkeKemPrivateKey recipientPrivateKey)
            throws java.security.GeneralSecurityException
        Extracts the shared secret from encapsulatedKey using recipientPrivateKey. Returns the raw shared secret. The HPKE RFC refers to this method as Decap(), which is used by the recipient.
        Throws:
        java.security.GeneralSecurityException - if the shared secret cannot be extracted.

      • authEncapsulate

        com.google.crypto.tink.hybrid.internal.HpkeKemEncapOutput authEncapsulate​(byte[] recipientPublicKey,
                                                                          HpkeKemPrivateKey senderPrivateKey)
                                                                   throws java.security.GeneralSecurityException
        Similar to encapsulate(byte[]), but the output additionally encodes an assurance that the KEM shared secret was generated by the holder of senderPrivateKey. Returns a HpkeKemEncapOutput object that contains the raw shared secret and the encapsulated key. The HPKE RFC refers to this method as AuthEncap(), which is used by the sender.
        Throws:
        java.security.GeneralSecurityException - when either the shared secret cannot be generated or the shared secret cannot be encapsulated.

      • authDecapsulate

        byte[] authDecapsulate​(byte[] encapsulatedKey,
                       HpkeKemPrivateKey recipientPrivateKey,
                       byte[] senderPublicKey)
                throws java.security.GeneralSecurityException
        Extracts the shared secret from encapsulatedKey using recipientPrivateKey. The recipient is assured that the KEM shared secret was generated by the holder of the private key corresponding to senderPublicKey. Returns the raw shared secret. The HPKE RFC refers to this method as AuthDecap(), which is used by the recipient.
        Throws:
        java.security.GeneralSecurityException - if the shared secret cannot be extracted.

      • getKemId

        byte[] getKemId()
         throws java.security.GeneralSecurityException
        Returns the HPKE KEM algorithm identifier for the underlying KEM implementation.

        More details at https://www.rfc-editor.org/rfc/rfc9180.html#name-key-encapsulation-mechanism.

        Throws:
        java.security.GeneralSecurityException