All three types of cryptography schemes have unique function mapping to specific applications. For example, the symmetric key( ) approach is typically used for the encryption of data providing ( ) , whereas asymmetric key cryptography is mainly used in key ( ) and nonrepudiation , thereby providing confidentiality and authentication. The hash ( ) (noncryptic), on the other hand, does not provide confidentiality but provides message integrity, and cryptographic hash algorithms provide message ( ) and identity of peers during transport over insecure channels.