# P384.Signing.PrivateKey A P-384 private key used to create cryptographic signatures. ``` struct PrivateKey ``` ## Topics ### Creating a private key [`init(rawRepresentation: Bytes) throws`](/documentation/CryptoKit/P384/Signing/PrivateKey/init(rawRepresentation:)) Creates a P-384 private key for signing from a collection of bytes. [`init(compactRepresentable: Bool)`](/documentation/CryptoKit/P384/Signing/PrivateKey/init(compactRepresentable:)) Creates a random P-384 private key for signing. [`init(derRepresentation: Bytes) throws`](/documentation/CryptoKit/P384/Signing/PrivateKey/init(derRepresentation:)) Creates a P-384 private key for signing from a Distinguished Encoding Rules (DER) encoded representation. [`init(pemRepresentation: String) throws`](/documentation/CryptoKit/P384/Signing/PrivateKey/init(pemRepresentation:)) Creates a P-384 private key for signing from a Privacy-Enhanced Mail PEM) representation. [`init(x963Representation: Bytes) throws`](/documentation/CryptoKit/P384/Signing/PrivateKey/init(x963Representation:)) Creates a P-384 private key for signing from an ANSI x9.63 representation. ### Representing the key [`var rawRepresentation: Data`](/documentation/CryptoKit/P384/Signing/PrivateKey/rawRepresentation) A data representation of the private key. [`var derRepresentation: Data`](/documentation/CryptoKit/P384/Signing/PrivateKey/derRepresentation) A Distinguished Encoding Rules (DER) encoded representation of the private key. [`var pemRepresentation: String`](/documentation/CryptoKit/P384/Signing/PrivateKey/pemRepresentation) A Privacy-Enhanced Mail (PEM) representation of the private key. [`var x963Representation: Data`](/documentation/CryptoKit/P384/Signing/PrivateKey/x963Representation) An ANSI x9.63 representation of the private key. ### Finding the public key [`var publicKey: P384.Signing.PublicKey`](/documentation/CryptoKit/P384/Signing/PrivateKey/publicKey) The corresponding public key. ### Creating a signature [`func signature(for: D) throws -> P384.Signing.ECDSASignature`](/documentation/CryptoKit/P384/Signing/PrivateKey/signature(for:)-8nncg) Generates an Elliptic Curve Digital Signature Algorithm (ECDSA) signature of the data you provide over the P-384 elliptic curve, using SHA-384 as the hash function. [`func signature(for: D) throws -> P384.Signing.ECDSASignature`](/documentation/CryptoKit/P384/Signing/PrivateKey/signature(for:)-wrsj) Generates an Elliptic Curve Digital Signature Algorithm (ECDSA) signature of the digest you provide over the P-384 elliptic curve. [`struct ECDSASignature`](/documentation/CryptoKit/P384/Signing/ECDSASignature) A P-384 elliptic curve digital signature algorithm (ECDSA) signature. ## Relationships ### Conforms To [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) --- 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)