Contents

init(recipientKey:ciphersuite:info:authenticatedBy:presharedKey:presharedKeyIdentifier:)

Creates a sender in authentication and preshared key mode.

Declaration

init<SK>(recipientKey: SK.PublicKey, ciphersuite: HPKE.Ciphersuite, info: Data, authenticatedBy authenticationKey: SK, presharedKey psk: SymmetricKey, presharedKeyIdentifier pskID: Data) throws where SK : HPKEDiffieHellmanPrivateKey

Parameters

  • recipientKey:

    The recipient’s public key for encrypting the messages.

  • ciphersuite:

    The cipher suite that defines the cryptographic algorithms to use.

  • info:

    Data that the key derivation function uses to compute the symmetric key material. The sender and the recipient need to use the same info data.

  • authenticationKey:

    The sender’s private key for generating the HMAC.

  • psk:

    A preshared key (PSK) that the sender and the recipient both hold.

  • pskID:

    An identifier for the PSK.

Discussion

The Sender encrypts messages in authentication and preshared key (auth_psk) mode using a symmetric encryption key that the sender and recipient both know in advance, in combination with a key it derives using a key derivation function (KDF) and the key schedule data in info. Messages also include authentication data so that the recipient can verify the authenticity of the sender’s private key.