Hello @aguynamedben. Both Common Crypto and OpenSSL are supported for macOS but you’ll likely have an easier time using Common Crypto. There are some cases where using OpenSSL on macOS is preferable, but they tend to be situations where an application already has other dependencies on OpenSSL, targets old versions of macOS, or has special security requirements (e.g. FIPS 140-2). For the general case Common Crypto is easier to work with.