Allthreetypesofcryptographyschemeshaveuniquefunctionmappingtospecific．Forexample,thesymmetrickeyapproach(本题)istypicallyusedfortheencryptionofdataproviding(),whereasasymmetrickeycryptographyismaidyusedinkey()andnonrepudiation,therebyprovidingconfidentialityandauthentication．Thehash()(noncryptic),ontheotherhand,doesnotprovideconfidentialitybutprovidesmessageintegrity,andcryptographichashalgorithmsprovidemessage()andidentityofpeersduringtransportoverinsecurechannels．
A.Cryptography B.decode C.privacy D.security正确答案A
