任何的mac算法都可以使用标准的hash功能，比如MD５或者sha－１，这种情况下，强度取决于hash功能，和最后的结果的比特串。密匙是关键。-HMAC is a message authentication code (MAC) and can be used to verify the integrity and authentication of a message. It involves hashing a message with a secret key. As with any

LTE密钥派生算法，HMAC-SHA-256-key derivation functon for LTE