Analysing the HPKE Standard.

The Hybrid Public Key Encryption (HPKE) scheme is an emerging standard currently under consideration by the Crypto Forum Research Group (CFRG) of the IETF as a candidate for formal approval. Of the four modes of HPKE, we analyse the authenticated mode \(\mathsf {HPKE}_\mathsf {Auth}\) in its single-shot encryption form as it contains what is, arguably, the most novel part of HPKE.