On Wed, 27 Aug 2025 20:00:54 GMT, Sean Mullan <[email protected]> wrote:
> > Hi Sebastian, the API you suggested is only the KEM step, and it should be > > made internal inside HPKE. > > At the end of the day, HPKE is still a cipher. I understand the key > > encapsulation message (aka, KEM ciphertext) is different from a traditional > > IV, but they share some key characteristics: 1) generated by the sender > > after initialization, 2) cryptographically random, 3) then made public, 4) > > has critical impact on encryption result. > > To avoid some of this potential confusion, I think it could help to expand on > the description of `Cipher.getIV()` to describe this new use case for IV, > something like changing this sentence: > > "This is useful in the case where a random IV was created, or in the context > of password-based encryption or decryption, where the IV is derived from a > user-supplied password." > > to: > > "This is useful in the case where a random IV was created, or in the context > of password-based encryption or decryption, where the IV is derived from a > user-supplied password, or in the case of HPKE (Hybrid Public Key Encryption) > where IV contains the encapsulation of the KEM shared secret." Good idea. Somehow I hesitate to update the base spec directly. Shall we put the whole paragraph into an `@apiNote`? A similar paragraph also appears in `CipherSpi::engineGetIV`. ------------- PR Comment: https://git.openjdk.org/jdk/pull/18411#issuecomment-3233196620
