Contents

Keys

Generate, store, and use cryptographic keys.

Overview

Cryptographic keys are strings of bytes that you combine with other data in specialized mathematical operations to enhance security. At the lowest level, this usually means participating in either encryption and decryption or digital signing and verification. You can use these basic operations directly, such as when you encrypt data before sending it through an insecure channel. You also use them implicitly, such as when you verify the digital signature on a certificate as a byproduct of a trust evaluation.

Keys vary based on the operations they support. For example, you use public and private key pairs to perform asymmetric encryption, whereas you use symmetric keys to conduct symmetric encryption. Similarly, one key might work for a 1024-bit RSA algorithm, while another might be suitable for a 256-bit elliptic curve algorithm. Use the functions in this section when you need to handle cryptographic keys.

Topics

Essentials

Key Generation

Examining Keys

Import and Export

Key Exchange

Encryption

Digital Signatures

Legacy iOS Key Operations

Legacy macOS Key Operations