Allthreetypesofcryptographyschemeshaveuniquefunctionmappingtospecific．Forexample,thesymmetrickeyapproach(71)istypicallyusedfortheencryptionofdataproviding(72),whereasasymmetrickeycryptographyismaidyusedinkey(73)andnonrepudiation,therebyprovidingconfidentialityandauthentication．Thehash(74)(noncryptic),ontheotherhand,doesnotprovideconfidentialitybutprovidesmessageintegrity,andcryptographichashalgorithmsprovidemessage(75)andidentityofpeersduringtransportoverinsecurechannels．
A.Algorithm
B.Secure
C.structure
D.encryption
正确答案是A