IPsec security uses two types of algorithms, authentication and encryption. The AH protocol uses authentication algorithms. The ESP protocol can use encryption as well as authentication algorithms. You can obtain a list of the algorithms on your system and their properties by using the ipsecalgs command. For more information, see the ipsecalgs(1M) man page. You can also use the functions that are described in the getipsecalgbyname(3NSL) man page to retrieve the properties of algorithms.
IPsec uses the Cryptographic Framework to perform encryption and authentication. The Cryptographic Framework enables IPsec to take advantage of hardware acceleration where the hardware supports it.