# HPKEPublicKeySerialization A type that [`HPKE`](/documentation/CryptoKit/HPKE) uses to encode the public key. ``` @preconcurrency protocol HPKEPublicKeySerialization : Sendable ``` ## Topics ### Initializers [`init(D, kem: HPKE.KEM) throws`](/documentation/CryptoKit/HPKEPublicKeySerialization/init(_:kem:)) Creates a public key from an encoded representation. ### Instance Methods [`func hpkeRepresentation(kem: HPKE.KEM) throws -> Data`](/documentation/CryptoKit/HPKEPublicKeySerialization/hpkeRepresentation(kem:)) Creates an encoded representation of the public key. ## Relationships ### Conforming Types [`PublicKey`](/documentation/CryptoKit/P521/KeyAgreement/PublicKey) [`PublicKey`](/documentation/CryptoKit/XWingMLKEM768X25519/PublicKey) [`PublicKey`](/documentation/CryptoKit/P256/KeyAgreement/PublicKey) [`PublicKey`](/documentation/CryptoKit/P384/KeyAgreement/PublicKey) [`PublicKey`](/documentation/CryptoKit/Curve25519/KeyAgreement/PublicKey) ### Inherits From [`Sendable`](/documentation/Swift/Sendable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) ### Inherited By [`HPKEDiffieHellmanPublicKey`](/documentation/CryptoKit/HPKEDiffieHellmanPublicKey) [`HPKEKEMPublicKey`](/documentation/CryptoKit/HPKEKEMPublicKey) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)