Security for Multihop Wireless Networks

140  ◾  Security for Multihop Wireless Networks

e standard defines three types of end entities named identified, identified not

localized, and WSA signers.

◾ Identified and identified not localized end entities are those entities that are

supposed to send secured application messages to other entities. ese end

entities have to obtain their certificates from the message CAs.

◾ WSA Signers are comprised of those entities that are supposed to send signed

WSAs. WSA signers receives their certificates from the WSA CAs.

An IEEE 1609.2 standard permits the encryption of a message before send-

ing the same to the recipient(s). e message sender uses symmetric key algorithm

to encrypt each message with a fresh symmetric key. e symmetric key is then

encr