---
title: "init(privateKey:ciphersuite:info:encapsulatedKey:authenticatedBy:presharedKey:presharedKeyIdentifier:)"
framework: cryptokit
role: symbol
role_heading: Initializer
path: "cryptokit/hpke/recipient/init(privatekey:ciphersuite:info:encapsulatedkey:authenticatedby:presharedkey:presharedkeyidentifier:)"
---

# init(privateKey:ciphersuite:info:encapsulatedKey:authenticatedBy:presharedKey:presharedKeyIdentifier:)

Creates a recipient in authentication and preshared key mode.

## Declaration

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

## Parameters

- `privateKey`: The recipient’s private key for decrypting the incoming 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.
- `encapsulatedKey`: The encapsulated symmetric key that the sender provides.
- `authenticationKey`: The sender’s public key for authenticating the messages.
- `psk`: A preshared key (PSK) that the sender and the recipient both hold.
- `pskID`: An identifier for the PSK.

## Discussion

Discussion The Receiver decrypts messages it receives in authentication and preshared key (auth_psk) mode using the encapsulated key with the key schedule information (info data), in addition to a symmetric encryption key that the sender and recipient both know in advance. Messages also include authentication data so that the recipient can verify the authenticity of the sender’s private key. note: The system throws errors from HPKE.Errors when it encounters them.