RFC 9180 · INFORMATIONAL · 2022

Hybrid Public Key Encryption

Overview

RFC 9180, “Hybrid Public Key Encryption”, is an Informational document published in February 2022 by R. Barnes, K. Bhargavan, B. Lipp, C. Wood. The canonical text is published by the RFC Editor.

Abstract

This document describes a scheme for hybrid public key encryption (HPKE). This scheme provides a variant of public key encryption of arbitrary-sized plaintexts for a recipient public key. It also includes three authenticated variants, including one that authenticates possession of a pre-shared key and two optional ones that authenticate possession of a key encapsulation mechanism (KEM) private key. HPKE works for any combination of an asymmetric KEM, key derivation function (KDF), and authenticated encryption with additional data (AEAD) encryption function. Some authenticated variants may not be supported by all KEMs. We provide instantiations of the scheme using widely used and efficient primitives, such as Elliptic Curve Diffie-Hellman (ECDH) key agreement, HMAC-based key derivation function (HKDF), and SHA2.

This document is a product of the Crypto Forum Research Group (CFRG) in the IRTF.

Abstract as published in the RFC, via rfc-editor.org.

What “Informational” means

Published for the general information of the community. It does not define an IETF standard and carries no standards-track status.

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